by Alexey Stepin , Yaroslav Lyssenko
02/08/2007 | 02:57 PM
The amount of memory a graphics card has on board is one of its main parameters along with the frequencies of the memory and GPU chips. At one time this parameter even determined which maximum resolution and color depth a graphics card could support in 2D applications. Thus, graphics cards with 1MB of memory could not use 32-bit color depth at all and supported 24-bit color depth in 640x480 resolution only. As the era of 3D games dawned, graphics memory also began to be used for storing textures and, eventually, other kinds of data, too.
Graphics processors and games evolving, the amount of data to be stored in the graphics card’s memory was ever increasing, and the manufacturers had to install more memory on their products. This made the end product more expensive, and an attempt to use system memory for storing textures was made. Thus, the i740 graphics chip, developed by Intel, would use the onboard memory only as a frame buffer while textures were stored in system memory and accessed by means of the GART mechanism (Graphics Address Remapping Table) described in the AGP bus specification.
However, AGP texturing never really took off because memory they then installed on graphics cards was already superior to system memory in speed characteristics whereas the storing of graphics data, even if some portion of them, in system memory had a very negative effect on the overall performance. As a result, the manufacturers returned to their earlier tactics and renewed the “weapons race”. Graphics cards with 64, 128 and 256MB of graphics memory appeared on the market eventually. Some unconscientious manufacturers used to play a nasty trick then: they put a lot of slow memory on inexpensive graphics cards and emphasized the amount of memory in the advertisements. This didn’t provide any real benefits, but could even lead to a performance hit if the memory clock rate was too low. Having purchased such a product with an impressive number on the box, the user would find out that it wasn’t nearly as fast as expected.
But as for top-end graphics cards with 128 or even 256MB of high-speed memory, the performance gain could be small or lacking altogether with them because their memory was not used fully. This amount of memory, 256MB, became useful and even necessary only when the new generation of games arrived and when gamers began to play in high resolutions and with enabled full-screen antialiasing. Finally, we’ve come to what we have now.
Today, 128 megabytes of graphics memory is the bare minimum for a modern graphics card. This amount is typical of the most inexpensive products that are not actually intended for regular gaming. Graphics cards positioned as gaming products are equipped with at least 256 megabytes of GDDR2/GDDR3 memory. Top-performance solutions come with 512MB of GDDR3/GDDR4 and new-generation graphics cards can boast as much as 640 or even 768 megabytes of memory. Solutions with 1GB of memory on board are about to arrive, too. But do today’s games really need that much? Let’s try to check it out.
The highly popular 3D shooter Doom 3 was the first game to declare that it needed 512 megabytes of graphics memory. The developer recommended using a graphics card with that much of memory to enable the Ultra High Quality mode. We did not, however, see any difference in performance between the High Quality and Ultra High Quality modes even in the resolution of 1600x1200 pixels with enabled 4x full-screen antialiasing (for details see our article called Doom III: Performance and Image Quality in Different Gaming Modes).
We also couldn’t see a performance breakthrough when we were benchmarking the first top-end graphics card with 512MB of memory, the ATI Radeon X800 XL 512MB, although it did perform better in a few tests like the legendary shooter Half-Life 2 in high resolutions with enabled 6x FSAA. It was clear that 512 megabytes of graphics memory was not in fact necessary and could only be of some use in high resolutions together with full-screen antialiasing. But in such modes the memory bandwidth and the performance of the GPU would became the crucial factors, limiting the card’s performance.
Our investigation was published back in the spring of 2005 and has become out-dated by now. Not one but several generations of graphics processors have changed since then. There have appeared new games with complex special effects that use Shader Model 3.0 and HDR whereas full-screen antialiasing has long become a customary image-enhancing option for most gamers who enable it wherever possible.
All these visual luxuries do not come cheap, for sure, but do they really require 512 megabytes of graphics memory? Answering this question, we should keep it in mind that many modern gaming projects are multi-platform ones or are planned to be such. And when you come to think of it, even the last generation of consoles like Microsoft’s Xbox 260 and Sony’s PlayStation 3 do not have as much memory as today’s gaming PCs. Game developers make allowances for that, reducing the resolution of textures. To make the game good-looking, they focus on special effects that are based on sophisticated math1ematical computations performed by the graphics processor. The GPU load is very high at that, but not much of graphics memory is employed since there are no huge textures. This trend is getting stronger nowadays and owners of graphics cards with 256MB of memory should not hurry as yet to upgrade to 512MB solutions.
Anyway, we want to see how things stand right now, and we are going to check out the influence of the amount of graphics memory on performance in today’s games. To carry out this investigation we’ll take two versions of the GeForce 7950 GT that suit our purpose perfectly. They are a Gigabyte GV-NX795T512H-RH with 512MB of memory and a Foxconn FV-N79GM2D2-HPOC with 256MB of memory. The Nvidia GeForce 7950 GT is an affordable and rather fast graphics card, so our investigation will have more practical worth. Let’s have a closer look at the two graphics cards now.
We have already seen the new packaging of Gigabyte’s graphics cards when we reviewed the GV-RX19X512VB (Radeon X1900 XTX) and GV-NX79X512DB (GeForce 7900 GTX) models as well as the unique GV-NX76T256D-RH “Silent Pipe II”.
Like each of the three mentioned products, the Gigabyte GV-NX795T512H-RH, hereafter referred to as just Gigabyte GeForce 7950 GT, comes in a rather big vertically oriented package. It is decorated to match the style of the strategy game Civilization IV enclosed in the box. There is a symbolic collage here that includes everything from Ancient Greek temples and Aztec pyramids to modern skyscrapers and space rockets. The package is painted rather mild colors and looks quite appealing.
Inside the vivid wrapping, there is an ordinary cardboard box with two compartments one of which contains a foam-rubber tray with the graphics card in an antistatic packet, discs and a user manual. The few accessories included with the product lie in the other compartment. Here’s a list of the box contents, besides the graphics card:
The user manual is written in two languages, English and Chinese. It gives you a detailed description of the installation procedure, also covering SLI configurations, and of the settings you can find in the Nvidia ForceWare driver, including information about the new Control Panel. The video output unit is a standard one, but Gigabyte added a sticker to it so that you could fasten it on the PC case. Most manufacturers are prone to forget about such trifles, and Gigabyte’s care about the user’s convenience looks appealing.
The lack of S-Video or RCA cables is not a drawback as it would have been a few years ago. These types of connections are but rarely used nowadays whereas YPbPr, DVI and HDMI, which ensure a much higher image quality, are ever growing in popularity. Besides that, cables that you usually find included with graphics cards are generally too short, making it impossible to connect your PC to a TV-set. The package doesn’t contain a power adapter, but we’ll explain this in the next section.
A copy of Civilization IV is a nice addition to this rather frugal set of accessories. This global turn-based strategy traces its origin back to the legendary Sid Meier’s Civilization released over 15 years ago, in 1991. This game is a universally recognized hit in its genre, so it’s good Gigabyte included it with its GeForce 7950 GT. One copy of a premium-class game is much better than a lot of demo versions or full versions of obsolete or unpopular games. Besides that, Civilization IV is a rather demanding application, especially if you play it at a high resolution with enabled full-screen antialiasing, and can outline the advantages of the GeForce 7950 GT over less advanced graphics cards.
Thus, the Gigabyte GeForce 7950 GT comes with good, but not extraordinary, accessories. This is not an expensive product, so we hadn’t really hoped for anything more.
As we wrote in our review of the Nvidia GeForce 7950 GT, Nvidia’s partners are not limited to utilizing the reference PCB design with that graphics card. Gigabyte took the opportunity and developed a product that has little in common with Nvidia’s reference card:
It’s clear that the PCB design of the Gigabyte GeForce 7950 GT was developed from scratch. There are a lot of differences, from the color of the lacquer that covers the PCB to the memory chips being turned around by 90 degrees. There is a standard 4-pin Molex plug instead of a 6-pin power connector typical of PCI Express graphics cards. That’s why you won’t find a power adapter among the card’s accessories.
The power circuit is fully redesigned: as opposed to the reference card, the power transistors are located on both sides of the PCB while the control elements were moved to the face side. These are NexSem NX2415 and NX2305 PWM-controllers that are responsible for powering up the GPU and memory, respectively. We haven’t yet seen such controllers in our labs. What’s interesting, the NX2415 typical connection schematic uses not only a +12V power line, but also a +5V one, so the appropriate pin of the Molex connector is really made use of. The +5V voltage powers up the controller itself and doesn’t seem to be used anywhere else, so the load on that line is very low. This power circuit design is most unordinary for graphics cards with a PCI Express interface which normally use +12V and +3.3V lines only.
The card carries eight chips of GDDR3 memory from Qimonda (ex-Infineon) that are marked as HYB18H512321AF-14. Each chip has a capacity of 512Mb (16Mx32), an access time of 1.4 nanoseconds and a voltage of 2.0V.
The chips are rated to work at 700 (1400) MHz and this is indeed the frequency they are clocked at on the Gigabyte GeForce 7950 GT, in full compliance with Nvidia’s specifications. The GPU frequency is exactly as specified by Nvidia, i.e. 570MHz for the vertex processors and 550MHz for the rest of the GPU subunits. So although the Gigabyte GeForce 7950 GT has a unique PCB design, its technical characteristics match precisely those of the reference card from Nvidia.
Among everything else we can note such things as the neat plastic plugs on all the external connectors as well as on the SLI connector. Note also the emblem telling us that the Gigabyte GeForce 7950 GT is manufactured using lead-less technologies.
Although the GPU and memory of the Gigabyte GeForce 7950 GT work at the frequencies of the reference card, this device is equipped with an advanced cooler, the VF700-AlCu model from Zalman. This is not a flagship product in Zalman’s line-up, yet it boasts a total ribbing area of about 500 sq. cm and a high-quality 80mm fan on two frictionless bearings. The heatsink is shaped like Zalman’s CNPS7x00 series coolers for the CPU, but is modified a little to adapt to the GPU geometry. The ribs are profiled in such a way that the bottom part of the heatsink is much smaller than its top part and the latter goes beyond the dimensions of the PCB. The bottom part won’t press against the mainboard, though.
The cooler is somewhat simplified in comparison with the retail version. First, the fan is adapted for a two-wire connection. Second, the memory chips lack heatsinks which are included with Zalman’s VF700-AlCu. And third, the cooler is fastened to the card without using a plate that would prevent the PCB from bending. The lack of memory heatsinks is not a problem because the cooler is designed in such a way as to cool the memory chips with the airflow from the fan. Moreover, modern GDDR3 memory working at frequencies about 700 (1400) MHz generates little heat and is quite capable of doing without any cooling at all. Having such an advanced cooler the Gigabyte GeForce 7950 GT should do well at overclocking, but the overall success will also depend on other factors like the frequency potential of the particular sample of the G71 chip and the overall design of the PCB.
We will check out the overclockability of our sample of the Gigabyte card in the appropriate section of the article. Right now we will examine the other graphics card that is about to take part in our today’s tests. It is the FV-N79GM2D2-HPOC model from Foxconn (hereafter referred to as Foxconn GeForce 7950 GT 256MB).
The package with the Foxconn GeForce 7950 GT 256MB resembles the above-described package with the Gigabyte card, but is decorated differently than packages from most other manufacturers:
This simplistic abstract picture is an eye-pleasing variation after so many monsters, robots and spaceships the other graphics card manufacturers like so much. The Foxconn card has every chance to attract a potential customer, so this design solution is justifiable.
There’s no valuable information on the front of the box, except for the mention of the card’s support of Windows Vista and the holographic sticker that informs the user that the card works at increased clock rates. The reverse side of the box tells you about Nvidia’s technologies and shows a comparative chart of performance of different GPUs from Nvidia. The diagram is not convincing, though. Its reference point is the result on a platform with an Intel Pentium 4 EE 3.73GHz while the rest of the data were obtained on a platform with an AMD Athlon FX-57 and with a rather old version of ForceWare into the bargain.
Here you can also learn what bonuses are included with the card.
Besides the graphics card proper, the box contains the following:
We guess the selection of the bundled software isn’t quite appropriate. The software for creating CD/DVD images and for system recovery after major failures is useful indeed, but we guess at least one third-person shooter would make a nice companion to the included gamepad.
This is a first-class gamepad with broad functionality as it has two analog joysticks besides the numerous buttons. As a matter of fact, game controller of that type are not very popular on the PC platform due to lack of third-person shooters and fighting games, the genres which are best played with a gamepad. Anyway, it makes a nice addition to the Foxconn GeForce 7950 GT 256MB.
The accessories to the Foxconn GeForce 7950 GT 256MB are sufficient, although the manufacturer might have enclosed one or two games, we guess.
As opposed to the above-described solution from Gigabyte, this graphics card is based on the reference design. It’s expectable since Foxconn is Nvidia’s main partner in manufacturing graphics cards.
The only difference you can spot with your eye is the lack of screening on the DVI-I connectors. Otherwise, the card from Foxconn is to the smallest detail identical to the reference one. The reference PCB design proved to be so successful that as many as three GeForce 7 models were based on it: GeForce 7900 GT, GeForce 7900 GS, and GeForce 7950 GT.
Just like the Gigabyte GeForce 7950 GT, the Foxconn GeForce 7950 GT 256MB uses GDDR3 memory from Qimonda, but its HYB18H256321AF-14 chips have a capacity of only 256Mb each, providing a total of 256 megabytes of graphics memory. The rest of the parameters of the memory chips coincide. The memory is rated to work at 700 (1400) MHz, but is clocked at a somewhat higher frequency of 780 (1560) MHz. There’s little reserve left for overclocking left.
The GPU frequency is increased above that of the reference card and is set at 580MHz (600MHz for the vertex processors). This should give the Foxconn an edge over the ordinary GeForce 7950 GT in those situations when the amount of graphics memory is not important. Since we are going to check out the influence of the amount of memory on performance, we will benchmark both cards at the reference frequencies. Note also that Foxconn also offers a similar card but with 512 megabytes of onboard memory. It differs from the discussed model with the characters 3D2 in its name. The non-overclocked versions have a simpler cooling system and the suffix HP instead of HPOC.
The reference cooler is known to be able to cope with the GeForce 7900 GS or GT easily, but it finds it very difficult to cool the core of the GeForce 7950 GT which is clocked at 550MHz. The GPUs of the pre-overclocked versions of the GeForce 7950 GT offered by Foxconn have an even higher frequency, so the company decided to install a more advanced cooler on such cards.
This cooler looks simple at first sight: a copper heatsink covered with a casing and equipped with a rather large fan.
However, the cooler from Foxconn has a special feature that helps it cope with the increased thermal load. We dismantled the cooler to show that feature to you:
As you can see, there is a flat U-shaped heat pipe in the cooler’s base. This pipe transfers heat from the copper piece that contacts the GPU die to the heatsink. The photo shows that there is a layer of dark-gray thermal grease in between the copper piece and the GPU die.
By the way, the cooler’s base is made not of copper, but of anodized aluminum as can be seen in the places where the cooler is fastened to the PCB. The memory chips are not forgotten, which is a rare thing for GeForce 7900 GT/GS and GeForce 7950. Here, the GDDR3 memory chips have contact with the cooler’s base through four elastic thermal pads. Their heat conductivity is probably low, yet that’s enough to cool the memory chips. At least, this is anyway better than if the chips were left without any cooling at all in the heat bag under the bottom of the cooler. The cooler is fastened to the PCB with four spring-loaded screws. That’s enough to secure it firmly since the cooler is rather small. There’s no danger that the PCB would bend or the GPU would get damaged by the cooler.
The cooler’s fan has a diameter of 70 millimeters and a consumption current of 0.39A. These characteristics are superior to those of the original fan in Nvidia’s reference cooler. The fan uses a 2-wire connection. It may be noisy if the speed management system is set up too aggressively, but we’ll check this out in the next section. Speaking in general, the cooler Foxconn installs on its pre-overclocked models of the GeForce 7950 GT has no obvious drawbacks and looks superior to the reference one.
We measured the level of noise produced by the coolers of the two different models of the GeForce 7950 GT with a digital sound-level meter Velleman DVM1326 (0.1dB resolution) using A-curve weighing. At the time of our tests the level of ambient noise in our lab was 36dBA and the level of noise at a distance of 1 meter from a working testbed with a passively cooled graphics card inside was 40dBA. We got the following results:
Even using a cooling system from Zalman, the Gigabyte GeForce 7950 GT turned to have rather poor noise characteristics. It is almost as loud as the GeForce 7900 GT that lacks a fan speed management system altogether. The Gigabyte card cannot change the speed of the fan, either, and is perfectly audible in any operation mode even at a distance of 1 meter from the working computer. The original VF700-AlCu makes use of an independent connection and is equipped with a FanMate speed controller, but here the fan is connected to the PCB directly and the fan connector would have to be replaced to use a rheobus.
The Foxconn GeForce 7950 GT 256MB behaves much quieter. Its results are closer to those of the GeForce 7950 GT’s original cooler with a working speed management, except that the fan on the Foxconn card has a constant speed. With a noise level of 40.7dBA, this graphics card is almost inaudible against the noises from other components of a typical gaming PC. So, this round of the competition is won by the Foxconn card, which produces little noise and is also smaller than the Gigabyte card because the Foxconn’s cooler has a smaller height.
But when it came to overclocking, the Gigabyte card was the only one to perform well. We could increase its GPU frequency to 680MHz and its memory frequency to 820 (1640) MHz. The Zalman cooler coped with the card easily. The Foxconn card was a disappointment as we could not raise its GPU frequency even by 10MHz, so we gave up all overclocking attempts. This may be a problem of our particular sample of the card (the GPU has low overclockability or the cooler’s base didn’t have proper contact with the GPU die), but you shouldn’t forget that the Foxconn FV-N79GM2D2-HPOC is already overclocked by the manufacturer, so its overclockability is lowered initially.
During our comparative testing of the Gigabyte GeForce 7950 GT and Foxconn GeForce 7950 GT 256MB we used the following hardware platforms:
The graphics card drivers were set up in such a way as to provide the highest possible quality of texture filtering.
We selected the highest possible graphics quality level in each game. We didn’t modify the games’ configuration files. Performance was measured with the games’ own tools or, if not available, manually with Fraps utility. We also measured the minimum speed of the cards where possible.
We tested the cards in three standard resolutions according to our testing methodology: 1280x1024, 1600x1200 and 1920x1200. We enabled FSAA and anisotropic filtering from the game’s menu. If this was not possible, we forced them using the appropriate driver settings of ATI Catalyst and Nvidia ForceWare. We didn’t run the tests with disabled FSAA, because our goal was to study the influence of the memory size on the performance and with FSSA enabled the requirements to graphics memory are higher. Moreover, the graphics accelerators reviewed today are powerful enough to ensure relatively high performance level with FSAA 4x.
We ran the tests with disabled FSAA only for those games that do not support FSAA due to the specifics of their engine or use HDR (FP16). The thing is that the GeForce 7 family cannot perform FSAA together with floating-point HDR.
Since our goal was to compare the performance of two graphics cards that only differed from one another by the amount of onboard memory, we reduced the clock frequencies of Foxconn GeForce 7950 GT 256MB to nominal values of 550/(700) 1400MHz. Besides two models of GeForce 7950 GT we had following graphics cards also participating in this review:
We used the following games and benchmarks:
First-Person 3D Shooters
Third-Person 3D Shooters:
There is little difference between the two versions of the GeForce 7950 GT despite the use of 4x full-screen antialiasing. It’s clear that the game doesn’t generate as much data even in 1600x1200 resolution as to make the difference in the amount of memory matter. Working at increased frequencies, the Foxconn GeForce 7950 GT 256MB (FV-N79GM2D2-HPOC) even leaves the Gigabyte card behind!
In spite of its increased frequencies, the Foxconn card is considerably slower than the Gigabyte from the beginning. The difference in performance between the cards with 256MB and 512MB of onboard memory does not depend on the memory clock rate in 1920x1200 resolution as is indicated by the results of the 256MB models. It’s clear the speed is limited by the amount of graphics memory.
The GeForce 7950 GT 256MB is slower than its opponent by 10-15%, depending on the memory clock rate, in the resolution of 1280x1024. The average performance being below 40fps, owners of such cards may have to disable full-screen antialiasing. But if you’ve got a GeForce 7950 GT with 512MB of memory, you can try to turn FSAA on. You won’t have a frame rate of 60fps, yet the gameplay will be much smoother.
The pre-overclocked product from Foxconn is a little faster than the Gigabyte, which works at the frequencies of the reference card, in every case, save for 1920x1200 resolution. At the same time, the imaginary GeForce 7950 GT 256MB graphics card is always slower than its 512MB counterpart.
Like in the previous case, the pre-overclocked graphics card from Foxconn is always ahead of the Gigabyte GeForce 7950 GT 512MB, except for 1920x1200 resolution. But if we take the GeForce 7950 GT with 256MB of memory and clocked at the reference frequencies, we’ll find it is always considerably slower than the same model with 512MB of memory, even though the speed it provides is high enough for comfortable play.
The difference between the graphics cards from Foxconn and Gigabyte is mainly due to the difference in the speed of the GPUs in the game’s FP HDR mode. The increased GPU frequency of the Foxconn card makes the trick here. Both cards are slightly better than the Radeon X1950 Pro, but much worse than the Radeon X1900 XT. There’s no difference between the cards form Foxconn and Gigabyte from a practical point of view: both can be used to play in resolutions no higher than 1280x1024.
Although F.E.A.R. is rightly considered one of the most demanding first-person shooters, its graphics memory requirements do not go beyond 256 megabytes even in 1600x1200 resolution with enabled full-screen antialiasing. The difference in performance between the Gigabyte GeForce 7950 GT 512MB and the graphics card that works at the same frequencies but has 256MB of memory amounts to 5% only, which is not important at all. Both cards are capable of providing an acceptable average and minimum frame rate in the resolution of 1280x1024 pixels. Note also that the pre-overclocked Foxconn GeForce 7950 GT 256MB is again somewhat better than the Gigabyte card.
Using the deferred rendering technique, this game is incompatible with full-screen antialiasing. There are only anisotropic filtering results here. Moreover, the game is too heavy to be run on graphics cards other than those of the high-end class, so we decided to use the resolution of 1280x1024 only.
The game doesn’t have much to show us in terms of graphics memory usage as it doesn’t support full-screen antialiasing and is a multi-platform project and, accordingly, doesn’t work with large textures. The results illustrate our point: the two cards that differ in the amount of graphics memory differ by only 0.6fps in speed whereas the pre-overclocked card from Foxconn has an advantage of 1.6fps over the product that works at the frequencies recommended by Nvidia.
Half-Life 2: Episode One behaves like the previous test, although it uses high-resolution textures besides shader-based special effects. It is only in 1920x1200 resolution that we can see a difference of 2.2fps. In all other cases the two versions of the GeForce 7950 GT that differ in the amount of graphics memory deliver identical performance. The increased frequencies of the Foxconn card have a small effect here.
Prey runs on an engine from Doom 3 , the first game to declare its use of 512 megabytes of graphics memory. However, this game seems to be quite satisfied with 256MB. The speed of the GeForce 7950 GT is limited by other factors, rather than by the amount of onboard memory, whereas the increased frequencies of the Foxconn GeForce 7950 GT 256MB in comparison with the reference card have a positive effect on performance.
Serious Sam 2 is known to be fastidious about the amount of graphics memory on board the graphics card. This is a consequence of the design of the game engine which uses high-quality textures and shaders with multiple texture lookups. As a result, the GeForce 7950 GT 256MB is over 20% slower than the Gigabyte card in 1280x1024 resolution and about 25% slower in 1600x1200 and 1920x1200. Although the increased frequencies improve performance of the Foxconn card, the Gigabyte card with 512 megabytes of memory is anyway much faster.
Thus, the necessity of having 512 megabytes of graphics memory is obvious in this test.
In this game 512 megabytes of graphics memory make a difference in 1920x1200 resolution only. But in that resolution the overall performance of graphics cards like GeForce 7950 GT/Radeon X1900 XT is too low for comfortable play, at least with enabled full-screen antialiasing. When it comes to more advanced solutions like Radeon X1950 XTX or the GeForce 8800 series, each of them is endowed with at least 512MB of memory and they won’t feel a lack of it in extremely high display modes.
The GeForce 7950 GT 512MB has a clear, but small, advantage over the graphics cards with 256MB of memory on board in Tomb Raider: Legend . The increased frequencies of the Foxconn card negate this advantage, though.
In other words, the graphics card’s having 512MB of memory doesn’t bring you any practical benefits despite the use of FSAA. This is expectable because the game is a multi-platform project and, as a consequence, uses math1ematical computations to create most of its special effects in the Next Generation Content mode. It doesn’t load graphics memory much because game consoles have but moderate amounts of it.
Note that the minimum speed of the GeForce 7950 GT cards is too low for you to have a comfortable gameplay even in 1280x1024 with enabled 4x FSAA.
The current version of Gothic does not support FSAA, so there are only anisotropic filtering results here.
Even without FSAA the game generates a huge amount of graphical data, but as it was the case with Hitman: Blood Money , the lack of memory only shows up in 1920x1200 resolution where the average speed of the ordinary GeForce 7950 GT is less than 20fps. However, this graphics card enjoys a 40% advantage over its 256MB counterpart. Even the increased frequencies of the Foxconn can’t help here. They only affect the card’s performance in 1280x1024resolution and provide a negligible gain of less than 1fps.
The game looks best with enabled HDR, so we benchmarked the cards in this mode. Moreover, the Nvidia GeForce 7 series cannot use FP HDR together with FSAA. We used version 1.3 of the game – its performance is improved over the earlier versions.
Even with patch 1.3, the average performance of the tested graphics cards is low and does not depend on the card’s having 256MB or 512MB of memory. The difference between the cards from Gigabyte and Foxconn is within the measurement error range and does not depend on whether the latter card works at its factory frequencies or at the frequencies of the reference GeForce 7950 GT.
The Nvidia GeForce 7 architecture doesn’t permit to use FP16 HDR along with full-screen antialiasing, but without HDR the game loses much of its visual appeal. That’s why we test the cards with anisotropic filtering only.
The average performance of the graphics cards from Gigabyte and Foxconn is identical, but the latter has a somewhat better minimum of speed in two out of three resolutions. But before making any verdict, let’s see the results on the open scenes of Cyrodiil.
Like in many other games, there is no difference between the different versions of the GeForce 7950 GT. So if the model with 256MB of memory has a considerably lower price, it would be wise to purchase it.
It’s almost the same here. We suppose that like in Far Cry ’s HDR mode the performance is limited by the speed of the ROPs and pixel processors. Working at increased frequencies, the Foxconn model shows a higher minimum of speed than the Gigabyte model despite the smaller amount of memory.
Radeon X1000 series cards do not support vertex texturing, so they can’t use the appropriate technology to render the water surface with the highest quality in this game. This is only available on Nvidia GeForce 7 GPUs.
The GeForce 7950 GT is limited by the CPU in 1280x1024 resolution, even though we turned FSAA on, but we can’t see the necessity of 512MB of graphics memory even in 1600x1200. The GeForce 7950 GT 256MB has the same results irrespective of the GPU and memory frequencies.
X3: Reunion boasts superb graphics, but doesn’t seem to use over 256MB of graphics memory. At least there is a negligible difference between the two versions of the GeForce 7950 GT, which have the same frequencies but differ in the amount of memory, in 1920x1200 resolution with enabled 4x FSAA, and there is no difference at all in 1280x1024. Working at increased frequencies, the Foxconn overtakes the Gigabyte card in high resolutions, but can’t leave it behind.
This sequel to Age of Empires 3 is quite satisfied with 256 megabytes of graphics memory and is more sensitive to the amount of pixel processors as is indicated by the results of the GeForce 7950 GT in comparison with the Radeon X1900 XT. The increased clock rates of the Foxconn GeForce 7950 GT 256MB don’t produce a big effect: this graphics card is only 1-1.5fps faster than the standard GeForce 7950 GT at best.
Being a real-time strategy, yet with the visuals of a first-person shooter, Company of Heroes naturally runs faster on a graphics card with more of graphics memory. This is especially conspicuous in 1280x1024 resolution where the Gigabyte GeForce 7950 GT is 25% ahead of its opponent. This gap is getting smaller in higher resolutions as other limiting factors enter the play, but the speed of the cards is too low even in 1600x1200 resolution for you to play in that resolution with enabled FSAA.
Although 3DMark05 defaults to 1024x768 resolution without full-screen antialiasing, there is a difference between the Gigabyte card and the GeForce 7950 GT 256MB that works at the reference frequencies. This difference amounts to a noticeable 535 points. This is not a surprise, however, considering that two out of the benchmark’s three game tests are rather large scenes. But if we compare the Gigabyte with the Foxconn working at its default frequencies (580MHz GPU and 1560MHz memory), it is the FV-N79GM2D2-HPOC that is better, by 133 points. Even though it is a small gap, it shows once again that the lack of 512MB of memory can be well made up for by higher GPU and memory frequencies.
Just as we had anticipated, the standard version of the GeForce 7950 GT has a considerable advantage over the “light” version of the same graphics card in the large-scene first and third tests, but smaller in the second test, which displays a rather small scene. The increased frequencies of the Foxconn GeForce 7950 GT 256MB make up for the lack of graphics memory. The numbers agree with the overall scores of the tested graphics cards, notwithstanding our using FSAA.
Although the graphics tests from 3DMark06 are actually modified tests from the 3DMark05 suite, the GeForce 7950 GT 256MB, at the standard frequencies, scores only 110 points less than the Gigabyte card. The Foxconn GeForce 7950 GT 256MB even scores 194 points more than the Gigabyte GeForce 7950 GT, which look right, considering its higher computing power.
In the SM2.0 tests the difference is as small as in the previous case. The Gigabyte card scores 50 points (or 2.5%) more against its 256MB opponent that works at the reference card’s frequencies. Working at its native frequencies, the Foxconn card scores 90 points more than the Gigabyte.
The difference is bigger in the SM3.0/HDR tests, but only amounts to 86 points or 4%. When the Foxconn card works at its native frequencies, it scores 72 points more than its opponent.
Unlike in the same situation in 3DMark05, the Foxconn GeForce 7950 GT 256MB is much slower than the Gigabyte GeForce 7950 GT in the second SM2.0 test when working at the reduced frequencies. The difference is 25% now. We can’t pinpoint the reason, but the abundance of vegetation and the use of high-resolution shadow maps and of a complex lighting model must have put a high load on graphics memory.
With the results of practical tests on our hands, we can claim that the GeForce 7950 GT doesn’t have an overwhelming advantage if equipped with 512 megabytes of graphics memory instead of 256 megabytes.
It’s only in four out of 19 tests that the Foxconn GeForce 7950 GT 256MB has been indeed considerably slower than the ordinary GeForce 7950 GT, namely in Call of Duty 2 , Serious Sam 2 , Gothic 3 , and Company of Heroes . But Serious Sam 2 is known to have an immoderate appetite due to very uneconomic rendering methods, and in Gothic 3 the difference could only be seen in 1920x1200 resolution in which the average speed of the GeForce 7950 GT with enabled 4x FSAA is less than 20fps. Thus, there are actually only two games left - Call of Duty 2 and Company of Heroes – that can really use more than 256 megabytes of graphics memory. In all other cases there is no benefit at all from 512MB of memory or it is seen only in high resolutions when graphics cards of the GeForce 7950 GT class cannot maintain a comfortable frame rate anymore. Graphics cards of a higher class already come with this amount of memory, or even more, so they don’t face that problem.
Of course, there are many more games available than what we use in our tests, yet we think 19 games is enough to reveal a trend. It is obvious here: 512 megabytes of graphics memory does not provide much benefit for a performance-mainstream graphics card like GeForce 7950 GT. Most of today’s games don’t really need more than 256MB. Or they need more memory in extreme display modes only when the GPU performance and the memory bandwidth are too low for comfortable play. You will really need 512MB of memory if you are going to play such games as Call of Duty 2 or Company of Heroes with enabled full-screen antialiasing.
Your choice should depend on the price factor: if the model with 256MB of graphics memory proves to be just a little cheaper than its 512MB counterpart, you should buy the latter. But if it is much cheaper, you should take the 256MB version, especially if it is clocked at increased frequencies, like the described Foxconn FV-N79GM2D2-HPOC: the difference in the amount of memory will generally be compensated with interest by the increased frequencies.
The Foxconn FV-N79GM2D2-HPOC is a good product. It comes with a high-quality and quiet cooling system, offers increased performance over the reference card and has good accessories, particularly a gamepad.
The Gigabyte GV-NX795T512H-RH is worthy of our praise, too. Having a non-standard PCB design, this card was 100% stable throughout our tests, delivering the performance of the reference GeForce 7950 GT and boasting good overclockability. Besides that, it features a highly efficient and high-quality cooler from Zalman and a copy of Civilization 4 as part of the bundled software. The only serious downside of the Gigabyte product is its rather high level of noise.