by Doors4ever
07/07/2008 | 11:36 AM
Detective stories and movies are usually pretty popular. A good detective novel appeals to your logic, imagination and lets you enjoy the author’s skill. At first you get acquainted with the main characters and can only guess who the killer is. As the plot develops, your suppositions may transform into certainty but by the end it inevitably turns out that the main suspect is innocent and the real killer is the one with rock-solid alibi, who we never even suspected.
Our today’s ZOTAC nForce 790i-Supreme mainboard review is pretty far from detective story-telling. However, throughout this article we had to change our opinion about he board so many times that detective genre came to mind.
Well, before we get to talking about the board, let’s say a few words about Nvidia nForce 790i Ultra SLI chipset it is based on.
The block diagram below will give you the most illustrative idea of the Nvidia nForce 790i Ultra SLI core logic. You can see right away that it is a really new chipset, because its predecessors used to have PCI Express 2.0 technology implemented in a separate Nvidia nForce 200 chip. Moreover, the memory controller now supports DDR3 memory modules.

By the way, only the official support of higher memory frequencies (DDR3 2000) differs this flagship chipset from the Nvidia nForce 790i SLI, which officially works only with DDR3 1333. In other words, Nvidia nForce 790i Ultra SLI chipsets have been specifically hand picked from the whole bunch of chips. The chipset specs are quite up-to-date, check for yourselves:

The above listed Nvidia nForce 790i Ultra SLI chipset specifications can be fully referred to ZOTAC nForce 790i-Supreme mainboard, because it is a reference mainboard following Nvidia’s own design. Of course, other similar mainboards selling under different names will only differ by the box design and accessories bundle.
ZOTAC Company did a great job on the mainboard packaging. The black cardboard box with a convenient carry handle is dressed up in a decorative external box designed in ZOTAC’s traditional golden-yellow color gamma.
The back of the box has a ZOTAC nForce 790i-Supreme mainboard photograph with the list of its major features.
All accessories are sorted out in separate boxes with ZOTAC logos.

ZOTAC nForce 790i-Supreme mainboard accessories bundle includes the following items:

There is a fan for the chipset North Bridge heatsink in a small black box. A Wi-Fi Kit is packed into a large black box and includes the following:
We have already reviewed mainboards with Wi-Fi modules. As a rule, the manufacturers provide them with special connectors or integrate onto the mainboard PCB, so it is very problematic or simply impossible to use them with any other mainboards. The advantage of a Wi-Fi kit from ZOTAC is that the card can be connected to a standard USB port with the included cable and so can work with any mainboard.
The usual beginning phrase about the mainboard looking good at first glance without any serious design flaws may have already become too boring, because it starts all our recent reviews. However, we should be pleased with the manufacturers’ success is designing mainboards, because practically all recently reviewed boards look superb and hardy have any design flaws. ZOTAC nForce 790i-Supreme will show beautifully how hard it must have been for Nvidia engineers to come up with a smart design and how brilliantly they coped with this task:
The chipset cooling system looks pretty interesting: it is designed as a single unit:
The chipset South Bridge heatsink is extended up to the North Bridge heatsink with heatpipes running beneath it. Heatpipes circle the processor socket and connect two additional heatsinks on top of voltage regulator MOSFET and a heatsink next to the memory DIMM slots. Of course, it may be challenging to install large processor coolers, but efficient chipset cooling is of utmost importance, too. This is also the reason why the chipset North Bridge heatsink has an extra section in it.

This cooling system ensures flawless operation in nominal mode. However, if you are up to overclocking, you may want to use an enclosed fan:

The fan casing is designed with special stops and a clip, so it can be easily installed and removed. It looks very stylish and goes well with the rest of the chipset cooling, however, this solution has two evident drawbacks. First, it will be hard to replace, if it breaks down. And second, it is too loud, despite the operation fan rotation speed management technology.
There was enough room in the lower part of ZOTAC nForce 790i-Supreme mainboard for two PCI, two PCI Express x1 and three PCI Express x16 slots. Two graphics card slots on the sides support PCI Express 2.0 x16, while the middle one is powered by the chipset South Bridge and also works at PCI Express x16 speed, though of the first version.
The storage media connectors are spread out in a little non-standard way. There is an IDE connector next to the 24-pin power connector. Then you see a horizontally positioned block including a FDD and two Serial ATA connectors. It is very convenient from the cable management prospective in case there are long graphics cards installed. The remaining four SATA connectors are closer to the top, next to the DIMM slots. The mainboard is equipped with a POST code indicator, Power On and Reset buttons. The connectors are all color-coded. The mainboard allows connecting up to 6 fans. The COM port is not available on the mainboard rear panel, but is aid out on the PCB. The sound is provided by and eight-channel Realtek ALC889 codec. There is also a Texas Instruments TSB43AB22A IEEE1394 controller and JMicron JMB362 SATA II controller with one port located right next to the PCI Express x1 slot. The second port is laid out on the rear panel in the form of an eSATA connector. The rear panel also has PS/2 connectors for keyboard and mouse, coaxial and optical S/PDIF, one IEEE1394 connector, two network RJ45 connectors and six USB 2.0 ports.

Please pay attention to the reverse side of the ZOTAC nForce 790i-Supreme mainboard PCB. We usually check if there are any electronic components there that could prevent s from installing the processor cooler backplate. This is not an issue in ZOTAC’s case. Besides, we noticed that the entire chipset cooling system is fastened with screws. There is not a single plastic clip that threatens to break every time you try to replace the chipset thermal compound, for instance.
In the meanwhile we would like to give due credit to Nvidia engineers for excellent job on the mainboard design: it is very logical and well-thought, all the details have been taken into account and all features are very attractive. In conclusion to our ZOTAC nForce 790i-Supreme PCB layout discussion we need to offer you the detailed list of its features and characteristics:

ZOTAC nForce 790i-Supreme mainboard, like other mainboards using reference design use BIOS on Phoenix-Award code. There are no built-in reflashing tools, like those on ASUS or Gigabyte mainboards. However, there is WinFlash utility that allows easily reflsashing the BIOS from Windows operating system even without a floppy drive. We tested the board with the latest BIOS version available at the time of tests: P05.

Advanced Chipset Features section contains a lot of useful overclocking friendly options.

The first subsection on the list is System Clocks. It allows changing the processor clock frequency multiplier and the information field will immediately report the resulting frequency. You can change the PCI-E bus frequencies, separately for two side PCI Express 2.0 x16 implemented by the chipset North Bridge and the middle PCI Express 1.0 x16 slot provided by the South Bridge. You can change the basic frequency of the HyperTransport bus between the chipset bridges as well as the data transfer rate from the North Bridge to the South and the other way around. Moreover, you can enable and disable Spread Spectrum for processors, HyperTransport bus, PCI Express buses from the North and South Bridges of the chipset and for Serial ATA.

FSB & Memory Config section allows setting the desired front side bus and memory bus frequencies. FSB speed is reported in quadrupled values and changes from 400 to 3000MHz, i.e. from 100 to 750MHz FSB in conventional measuring units.

In Unlinked mode we can set the memory frequency to any number from 400 to 2500 (!) MHz with a very small increment. In Linked mode there are only three dividers to choose from:

The corresponding information fields will report the resulting values after every frequency change, so it is very easy and convenient to work with the FSB & Memory Config subsection.
P1 and P2 parameters maybe set to Auto or Enabled. They appeared only in the latest BIOS version that is why there are no descriptions of these parameters in the paper and electronic mainboard manuals. And Memory Timing Setting parameter opens a separate page with adjustable memory timings.

As you see, the features a superb: there are a lot of adjustable parameters, each can be changed independently of the rest, all the current and resulting values are immediately displayed.
The next subsection in the Advanced Chipset Features section is called CPU Configuration and offers to control processor technologies and disable idling processor cores.

You can change voltage settings in the System Voltages subsection. It is extremely convenient that the current values of each parameter are displayed in a separate column right there:

Another advantage is the use of color indication: relatively safe values will be green, while high values will be red.

The voltages can be changed in the following intervals:
NVMEM memory test from the Advanced Chipset Features is disabled by default, but it can be set to Fast, Medium or Slow. In this case the memory test on system boot-up will be performed faster or slower.
The next couple of parameters called Load timing/voltage set and Save timing/voltage set allow saving and loading three BIOS settings profiles.

Unfortunately, there are two serious drawbacks here. Firstly, you can’t name the profiles or add a detailed description to them, i.e. you have to remember what profile contains what type of settings. Secondly, not all the BIOS settings are saved, but only the Advanced Chipset Features part including FSB frequency, memory timings, CPU Configuration settings. However, the memory divider will not be saved. Of course, even this limited functionality is better than nothing, however, other mainboards may have something better to offer in this respect.
The options in most BIOS sections are pretty standard and should be pretty easy to configure. The next section after Advanced Chipset Features that we should dwell on is called System Monitor:

It offers pretty decent functionality, the best being CPU Current. It demonstrates how the processor power consumption would increase if CPU Core voltage did. Here you can control rotation speed of five fans out of six that can be connected to the board. To work with them you need to switch to Dynamic Fan Control page.

CPU Fan, Chassis Fan and nForce Fan rotation speeds change automatically depending on the temperatures. You can adjust the settings for the first two. Moreover, you can set the rotation speed of all five fans at a fixed rate in percents from the nominal. Unfortunately, the processor fan rotation speed may only be controlled and adjusted if the fan has a four-pin connector.
Overall, despite a few drawbacks we pointed out, ZOTAC nForce 790i-Supreme mainboard boasts very good BIOS functionality. There re a lot of options, the supported ranges are big enough, all settings and very well-thought and illustrative. As you remember, we were also very pleased with the mainboard accessories bundle and PCB layout. Now we have to discuss the most interesting part: we have to see how all these advantages play in real applications and tests.
All our tests were run in an open testbed with the following configuration:
First of all we decided to find out how high we could push the FSB frequency for ZOTAC nForce 790i-Supreme mainboard to remain operational and stable. Therefore, we increased the FSB voltage, memory bus voltage and NB voltage and lowered the Intel Core 2 Duo E8400 processor frequency multiplier to the minimal x6. The board started at 475MHz and 450MHz FSB, but failed to load the OS. It all ended with inevitable BSOD and “Machine Check Exception” error. Only at 425MHz FSB we could finally see the Windows desktop.
Well, here is the first disappointment. Despite the promises, this mainboard proved hardly fit for processor overclocking. Luckily, we noticed that at some point processor clock frequency multiplier in the CPU-Z window suddenly hanged to x9 and then returned back to x6. Basically it was not enough to set the CPU multiplier in the BIOS. We had to disable the EIST for the multiplier to stay where we set it. Of course, the CPU couldn’t work at 450MHz FSB and 475MHz FSB without the corresponding core voltage increase It was really surprising that it managed to boot Windows at 425MHz FSB in this case.
By the way, EVGA nForce 750i SLI FTW mainboard also based on Nvidia reference design showed the same result during our preliminary tests. Since these two mainboards have similar BIOS, it could be exactly the same problem that wouldn’t let us go any further. I guess we will have to double-check it.
Once we unveiled this peculiarity of the BIOS from the reference Nvidia boards, finding maximum operational FSB frequency went on much faster. ZOTAC nForce 790i-Supreme mainboard successfully passed 450, 475 and 500MHz FSB with the processor multiplier reduced to x6. Then the progressed stopped. At 515MHz FSB the system booted and worked for a while, however, we had to go down to 510MHz with the Intel Core 2 Duo E8400 overclocked to its maximum with x8 multiplier. Well, 510MHz is not record-breaking frequency, but it is nevertheless a very good result. At this point we considered ZOTAC nForce 790i-Supreme a good mainstream overclocker solution and decided to move on to experiments with quad-core processors. However, this is where the surprises started.
Of course, most mainboards overclock dual-core processors much better than quad-core processors. Overclocker mainboards usually stop at about 450-460MHz FSB, while non-overclocker boards may not hit even this frequency. So far the best result in dealing with our Intel Core 2 Quad Q9300 processor belonged to abit IP35 Pro mainboard: 475MHz FSB, and there wasn’t a single mainboard out there that could get even close to that. Therefore, we started with 475MHz FSB and intended to lower the frequency little by little in order to find what our ZOTAC nForce 790i-Supreme was capable of. However, the board passed the tests at 475MHz and 485MHz FSB and stalled only at extremely high frequency for quad-core CPUs of 495MHz! We couldn’t hit the beautiful 500MHz, however, it doesn’t make the performance of our ZOTAC nForce 790i-Supreme any less impressive.

To reach this extremely high frequency we had not only to adjust a few voltages (processor Vcore - to 1.475V, FSB voltage – to 1.4V and NB voltage to 1.5V), but also to play with the GTLVREF parameter. By the way, it was the first time in my experience when changing these parameters actually improved overclocking performance. Otherwise I would have had to stop at 490MHz.
No one knows what GTLVREF values the mainboards set. Only those know who have reference mainboards on Nvidia chipsets, because they do display these values. Their BIOS is indeed very informative. We noticed that when our Intel Core 2 Quad Q9300 processor was working in its nominal mode, the board set
I would like to say a few words about FSB Hole right away: we found no frequency intervals where ZOTAC nForce 790i-Supreme mainboard would be non-operational. However, they do exist or at least existed. Here is what they say about the BIOS P05: "Fix isolated corruption issues around certain non-stock FSB/DDR3 configurations near 1600 MHz". So, there were some problems around 400 (1600) MHz but they were eliminated.
As for FSB Strap, when at some point during overclocking performance drops, we checked it out by testing the read speed from the memory subsystem in Everest program. The memory divider and timings were locked, the processor clock frequency multiplier was reduced to x6. We used a dual-core Intel Core 2 Duo E8400 processor, which ZOTAC nForce 790i-Supreme mainboard can overclock to 510MHz FSB. So, we started testing at this frequency and then got 10MHz lower with every step. The memory frequency reduced accordingly, and so did the read speed. Everything went on nice and easy until we hit 450MHz FSB, where performance suddenly jumped up.

We took a closer look at this problem and found out that the performance drops when we move from 450MHz to 451MHz FSB. AT 450MHz FSB the read speed is 8295MBps, and at 451MHz it drops to 7054MBps. This notorious threshold didn’t go away, no matter what memory timings or dividers we set. Only the absolute read speed value changed, however, it still dropped down dramatically when moving from 450MHz to 451MHz FSB.
The saddest thing is clearly seen from the graph above: overclocking doesn’t make up for the performance drop. Even when we are at maximum 510MHz, FSB the read speed is lower than it used to be at 450MHz. So, it doesn’t make sense to overclock past 450MHz on ZOTAC nForce 790i-Supreme mainboard. So, looks like we won’t be able to really enjoy its good dual-core and excellent quad-core processor overclocking potential.
Now we have to figure out one more thing: in what conditions we should measure ZOTAC nForce 790i-Supreme mainboard’s performance? Our Intel Core 2 Duo E8400 processor can overclock to 4.1GHz and this value can be reached several different ways. So, we considered four possibilities here:
Strange as it might seem, but all four situations turned out pretty close in terms of performance. However, we will have to disregard the memory tests in Everest, because in this case the first options becomes a real favorite, at lest until FSB Strap kicks in. In other test applications the performance difference was minimal, unlike FSB Strap on Intel 965P Express, where it has serious effect on the performance in majority of applications. Therefore, we decided not to draw any conclusions just yet and check out the results demonstrated by the competitor mainboard.
You already know fro the description of our testbed that we picked ASUS Maximus Extreme on Intel X38 Express to be the opponent in our today’s test session. There are a few reasons for this decision: it also supports DDR3 SDRAM, it overclocks CPUs well, you can increase its performance beyond average with Ai Clock Twister and Ai Transaction Booster parameters. MSI X48 Platinum mainboard on a more advanced Intel X48 Express chipset doesn’t have any of these features. Besides, it works poorly with the memory leaving Command Rate to 2T at all times, no matter what you set in the BIOS. Moreover, good mainboards on contemporary Intel chipsets, such as Intel X48 Express, Intel X38 Express and Intel X35 Express, perform almost identically. So, it is absolutely alright that we will compare ZOTAC nForce 790i-Supreme on NVIDIA nForce 790i Ultra SLI chipset against ASUS Maximus Extreme on not the very latest Intel core logic set.
The only problem was to find two more or less comparable operational modes for both mainboards. ZOTAC nForce 790i-Supreme works with 1800MHz memory with 8-8-8-24-1T timings, while ASUS Maximus extreme hasn’t been able to do the same so far.
Attention! If you are using two memory modules on an Nvidia nForce 790i Ultra SLI based mainboard with reference PCB design, you should better install them into those two DIMM slots that are the farthest from the processor socket: the second and the fourth one. In this case you will be able to hit higher frequencies at more aggressive timings than in case the modules sit in the “closest” slots – the first and the third. Theoretically, this rule should also work for other mainboards supporting DDR3, too, however, we need to double-check that before stating anything.
Unfortunately, nothing could help us get our ASUS Maximus Extreme to work stably with 1800MHz memory: we tried reflashing the BIOS with the latest available version and even moving the memory modules into the farthest slots. When we overclocked our Intel Core 2 Duo E8400 to 455MHz FSB with the default multiplier of x9, the memory frequency was only 1517MHz. However, we managed to set Ai Transaction Booster to +5 and lower the timings to 7-7-7-18-1T. This answered the question about the best operational mode for a fair comparison against ZOTAC nForce 790i-Supreme: it didn’t matter how our mainboard on NVIDIA nForce 790i Ultra SLI would work, if it still lost to the competitor no matter what.
So, we completed our test session. And looks like ZOTAC nForce 790i-Supreme mainboard boasts great accessories bundle, excellent PCB layout and functionality, good BIOS options, good dual-core processors and phenomenal quad-core processors overclocking potential. However, it suffers from FSB Strap and doesn’t perform very well. Doesn’t sound very optimistic, does it?
Yes, it does! Do you recall the mysterious undocumented P1 and P2 parameters in the FSB & Memory Config section that are set at Auto by default? It turned out that if you set them to Enabled, the mainboard will mysteriously transform. First, FSB Strap will vanish. And second, and this is the most important thing, the mainboard performance will increase so greatly that it will catch up with that of an Intel X38 Express based platform!
Here are the CPU and memory settings on our ZOTAC nForce 790i-Supreme mainboard:


And these are the same operational settings on our ASUS Maximus Extreme (MemSet utility doesn’t detect the memory frequency correctly, though):


And here are the results:

For a more illustrative comparison we highlighted the best results, however, the difference is very often within the measuring error anyway. As we see, Nvidia nForce 790i Ultra SLI based mainboard is as fast as the high-performance Intel X38 Express based one during overclocking.
We have spoken a lot of power consumption lately with ASUS mainboards being a negative example. Once the processor core voltage on these mainboards is changed, Intel power-saving technologies stop working. In the meanwhile, Vcore often needs to be increased for the sake of better overclocking results. However, mainboards on Nvidia chipsets turned out to be wasting even more power.
ASUS mainboards have “smart” BIOS. During relatively low overclocking to a certain point, it doesn’t interfere. At higher frequencies it starts increasing processor Vcore, Vmem, Vchipset: the higher you overclock, the more the voltages increase. Reference mainboards on Nvidia chipsets cannot boast a smart BIOS. Even during insignificant processor overclocking (for example, from 1333MHz FSB to 1350MHz) it will immediately increase the processor, FSB bus and chipset voltages. After that these voltages do not increase any more for the sake of further successful overclocking, no matter how far you push the frequencies, however, this initial increase is more than enough for Intel power-saving technologies to shut down. Too bad.
Nvidia based mainboards have always been known for their power-hungry temper, and during overclocking their power consumption rates will depends a lot on the voltage settings. For the sake of fair comparison we will measure power consumption wit the CPU working in its nominal mode, when the power-saving technologies work on all boards.
For this test we used Extech Power Analyzer 380803. It is connected even before the power supply unit, so the results it shows reflect the power consumption of the entire system without the monitor. We used processor FPU-test from S&M 1.9.1 utility to check the power consumption under load.

Nvidia nForce 790i Ultra SLI based mainboard consumes a little more power than Intel X38 Express based board, however, the difference is really small. Nvidia chipsets will most likely become more economical with the time, but even at this point, power consumption doesn’t determine the chipset choice. What is truly remarkable, that the mainboard based on a flagship core logic set consumes considerably less power than a board on a more mainstream chipset from the same series! This can certainly be partially explained by lower power consumption of DDR3 SDRAM DIMMs, however the main power-consuming knot on the Nvidia nForce 750i SLI based mainboard is definitely the Nvidia nForce 200 bridge. As you remember, Nvidia nForce 790i Ultra SLI doesn’t have it. Aren’t you surprised that ASUS claims its P5N-D mainboard boasts great energy efficiency? However, ASUS P5N-D mainboard is not the topic of our today’s review, we have already discussed it in one of our previous articles.
Well, at first glance ZOTAC nForce 790i-Supreme mainboard looks like a really excellent product. It deserves our highest score for great accessories bundle, excellent PCB design and extensive functionality, functional and very convenient BIOS. The mainboard overclocks dual-core processors pretty well and demonstrates impressive success with quad-core CPUs overclocking. Its performance is very close to that of the best mainboards on competitor chipsets and power consumption is just a tiny bit higher. Does it mean that we have finally found an ideal mainboard? I don’t think so. Objective reality forces us to dethrone this evident favorite.
It is not those few drawbacks that we found about ZOTAC nForce 790i-Supreme mainboard. Any mainboard has them. The mainboard cannot control the rotation speed of fans with three-pin connectors, doesn’t save the complete BIOS settings profiles. These are small things, but the disabling of Intel’s power-saving technologies during overclocking may be a significant thing for many users and unfortunately, there is no way of solving this problem. However, even if this is not a big issue for you, there remains one more: the board is based on an Nvidia chipset.
Unfortunately, new mainboards on Nvidia nForce 790i Ultra SLI chipset inherited a critical issue of their predecessors: they lose and corrupt data. New BIOS updates may seem to have resolved this issue, but isolated incidents still occur, and I doubt you would want to take the risk of becoming the unlucky one, so don’t trust Nvidia based mainboards with your valuable data. It is really puzzling why Nvidia hasn’t yet updated their South Bridges, which contain hard disk drive controllers.
We didn’t manage to track down the FSB Hole, but it did exist. FSB Strap is no longer there, but where did it move – up or down – or maybe it disappeared indeed? No one knows for sure what new processors Intel will roll out considering the changing market situation, but will Nvidia based mainboards support them? We still remember those unfortunate examples. To our regret, Nvidia nForce 790i Ultra SLI cannot be called reliable. And until these negative tendencies are exterminated, mainboards on Nvidia chipsets will not become a real mass product. And I really sympathize with SLI fans who are forced to buy platforms like that. It is a real pity that because of severe chipset issues a lot of users will give up the idea of getting an Nvidia based board. Especially, since ZOTAC nForce 790i-Supreme mainboard is a remarkably successful product.