Design and Specifications
The first GeForce GTX 460 to come to our test lab has nothing in common with the reference card from Nvidia. It is a unique product from Gainward that relies on the research and development capabilities of Palit Microsystems. Unfortunately, we cannot compare the new card directly with the reference sample but we know that the Gainward version is somewhat shorter, which is indisputably good.
The card has nothing in common with the GF100-based monsters as it is compact and can be easily installed into any system case that can accommodate a dual-slot graphics card. Owners of compact barebone systems should appreciate that. The GeForce GTX 460 will help them build an advanced but small gaming computer. As usual, the most interesting things can be found under the cooler’s heatsink.
The rectangular GPU is highly unusual. We have not seen a GPU package shaped like this before. The power circuit is rather simple. You can see four voltage regulator phases with three transistors in each. There is a seat for a fourth transistor, so this power system can be reinforced if necessary.
This seems to be a 4+1 design. That is, there is a four-phase GPU voltage regulator plus a single-phase memory voltage regulator. Considering the factory overclocking, the use of a 4-phase regulator instead of the reference card’s 3-phase one is justifiable.
The power subsystem is managed by two controllers: a NCP5395T chip from ON Semiconductor and a RT9259B from Richtek Technology. The former is responsible for the GPU and the latter for the graphics memory. The card has two 6-pin PCIe 1.0 connectors for power cables. We guess a single 8-pin PCIe 2.0 connector with its higher load capacity would be quite enough but the engineers from Nvidia and Palit do not agree with us. By the way, these connectors are located at the shorter edge of the PCB on the reference card, making it less easy to plug the cables in. It is good that the Palit/Gainward developers moved them to the top edge.
The memory chips are placed in an unusual way. One of the eight chips is separate from the others, residing close to the DVI connectors. We haven’t seen such a component layout before.
The K4G10325FE-HC05 chips from Samsung have a capacity of 1 Gb (32 Mb x 32) and a rated frequency of 1000 (4000) MHz. As we already know, the default memory frequency of the GeForce GTX 460 is 900 (3600) MHz but Gainward pre-overclocked its GeForce GTX 460 GS GLH to 1000 (4000) MHz, raising the peak memory bandwidth to 128 GBps, i.e. to the level of the Radeon HD 5830 and 5850. The total amount of graphics memory is 1 gigabyte, which should more than enough to satisfy every modern game. The card can drop its memory frequency to 324 (1296) MHz or to 135 (540) MHz in its two power-saving modes. The former mode is meant for such medium-load applications as HD video decoding and the latter is for low loads such as Windows desktop applications.
So, the new GF104 chip is unusually rectangular. As is typical of Nvidia products, the die is covered by a heat-spreading cap. According to the marking, this sample was manufactured on the 10th week of the current year, so this is a second revision. The first revision, which does not usually go into mass production, would be called A0. The revision number suggests that Nvidia had no serious problems developing the GF104. The Gainward card is pre-overclocked from 675/1350 MHz to 800/1600 MHz and this should ensure a good performance boost in games. You will see the exact value of that boost in our gaming tests. The GPU voltage is 0.987 volts in 3D applications, 0.912 volts in the video decoding mode and 0.875 volts in the desktop mode. The GPU clock rates are reduced in the latter two modes to 405/810 and 51/101 MHz, respectively. Coupled with its 40nm tech process, the GeForce GTX 460 should be a very economical device. We will check this out in the next section of our review.
The current version of the GPU-Z utility does not tell the GF104 specs right, reporting only 224 ALUs whereas the chip actually has 336 active ALUs out of the physically present 384. Thus, only seven out of the eight multiprocessors are enabled while the disabled unit may serve as a reserve for Nvidia. For the same reason, the number of texture-mapping units is 56 rather than 64 while the rasterization subsystem consists of 32 RBEs that delivers a high scene fill rate, especially considering the pre-overclocked frequency of 800 MHz. In fact, the GF104 chip overclocked to 800/1600 MHz does not have any apparent bottlenecks. We guess in its hypothetical full configuration with 384 ALUs and 64 TMUs it would be even competitive to the RV870 in the Radeon HD 5870 card.
As opposed to the reference sample, the Gainward GeForce GTX 460 GS GLH natively supports nearly all modern interfaces save for DisplayPort. The manufacturer calls this QuattroPorts but it doesn’t mean that you can connect up to four monitors to the GeForce GTX 460 GS GLH simultaneously. Like with all other products with Nvidia GPUs, you can only use dual-monitor configurations with the single graphics card. Anyway, it is good that the card has a full-size HDMI connector instead of a mini-HDMI that would require an adapter.
As for SLI support, GF104-based cards are equipped with only one MIO connector and cannot be used in multi-GPU configurations with more than two devices. That’s not a serious downside since even a pair of SLI-linked GeForce GTX 460 cards is theoretically faster than a single GeForce GTX 480. As noted above, the GF104 is the first GPU from Nvidia to support Protected Audio Path and to match AMD’s solutions in terms of working with multichannel HD audio formats.
The cooling system deployed on the Gainward GeForce GTX 460 GS GLH is far from original. It represents a popular design with a large axial fan placed in the card’s center. If you undo the four screws and take off the plastic casing with fan, you will see the following:
The copper base carries a heatsink consisting of interlocked slim aluminum fins. It is connected to the heat-exchanger with two heat pipes. The heatsink is surprisingly low in profile yet should be enough to cool a GF104. The separate black aluminum heatsink, secured on the PCB with three screws, removes the heat from the power transistors of the voltage regulator via a green elastic thermal pad. A layer of dark-gray thermal grease is applied between the heat-exchanger and the GPU cap.
While we dismantled and then reassembled the cooler, we scraped off the thermal grease from the GPU and cooler and applied a fresh layer of KPT-8 grease. The cooler’s fan was manufactured by Power Logic.
We know the PLA08015B12HH model by the Palit GeForce GTX 470 card we tested in an earlier review. Practice suggests that such fans are efficient and not very loud, so the Gainward GeForce GTX 460 GS GLH can be expected to be quiet. The cooling system seems efficient overall but it does not exhaust the hot air out of the system case. The slits in the card’s mounting plate do not help much. Most of the hot air goes out near the card’s power connectors. Therefore you should make sure you system case is properly ventilated if you want to install a Gainward GeForce GTX 460 GS GLH into it.
So, that’s the end of the theoretical part of this review. We will now proceed to examine our graphics card in practical tests.