EVGA nForce 790i Ultra SLI Review April 10, 2008 Chris Crazipper Angelini

Introduction

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I’m a platform guy. I like the pieces of my gaming and business machines to come from the same company whenever possible. That’s one proverbial neck to wring when something goes wrong. Even more important is the research and development that goes on under one vendor’s roof. You expect that when Intel designs a chipset for its processors, the two are tested extensively together. The same goes for AMD and its processors, core logic, and graphics cards. If there’s one thing I’ve learned from writing for the channel it’s that there’s real value in selling platforms centering on components all validated together.

We’ve already lauded the Phenom/790FX combo for its enthusiast allure and Intel’s Core 2 Quad/X48 is shaping up to be a formidable high-end solution as well. Now NVIDIA is looking to reassert itself in the chipset arena—a market the company once dominated. Granted, NVIDIA doesn’t have the CPUs it’d need for a conventional platform play. It does have chipsets, motherboards designed in-house, and a full line of GPUs to attract enthusiasts who share my platform affinity, though.

Meet the 790i

Now it’s the 790i’s time to shine. If you bought a 780i board in the last couple of months, it’s already getting replaced by a chipset with built-in PCI Express 2.0 connectivity, DDR3 support, and an official 1600 MHz FSB setting. Of course, there’s also 3-Way SLI to talk about, in addition to compliance with NVIDIA’s ESA architecture.

LGA775 Enthusiast North Bridges
	Intel X48	Intel P35	NVIDIA 790i Ultra SLI	NVIDIA 790i SLI	NVIDIA 780i SLI
Memory Support	DDR2 (800)/DDR3 (1600)	DDR2 (800)/DDR3 (1333)	DDR3 (2000)	DDR3 (1333)	DDR2 (1200)
Front Side Bus Speeds	1600/1333/1066/800	1333/1066/800	1600/1333/1066	1600/1333/1066	1333/1066/800
Multi-GPU	CrossFire	CrossFire	Quad/3-Way SLI	Quad/3-Way SLI	3-Way SLI
PCI Express	32 lanes, PCIe 2.0	16 lanes, PCIe 1.1	32 lanes, PCIe 2.0	32 lanes, PCIe 2.0	32 lanes, PCIe 2.0

Should you fret over the quick replacement? Nah. The 780i’s DDR2 slots make it a cost-effective choice even today. DDR3 is still quite pricey and the 780i’s sanctioned 1333 MHz front side bus is, for the most part, top-of-the-line. You get 3-Way SLI and support for the latest 45nm Penryn-family chips. There’s still every reason to feel good about buying a 780i board—especially if you were in the market for NVIDIA’s multi-card rendering technology and are now merrily cruising along with a double- or triple-barreled GPU configuration.

With all of that said, there’s a new sheriff in town, so step aside junior…err, 780i.

New Features and Some of the Same

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A Fresh SPP, or Two

NVIDIA’s 790i introduction actually consists of two chipset offerings: the nForce 790i Ultra SLI and the nForce 790i SLI. The former uniquely accommodates 2,000 MHz DDR3 memory modules, whereas both solutions share the higher-speed FSB option, PCI Express 2.0, and the circuitry needed for 3-Way SLI.

Let’s start from the top of NVIDIA’s 790i block diagram and work our way down.



As mentioned, both 790i SPPs (system platform processors—the equivalent of a north bridge) are able to communication with Intel Core 2 Extreme, Quad, and Duo CPUs over a 1600 MHz front side bus. Where’s AMD’s processors incorporate integrated memory controllers, Intel’s do not. Thus, the 790i sports its own built-in controller circuitry. This is NVIDIA’s first attempt at DDR3 support, so it’s pretty amazing that we’re seeing up to 2000 MHz right off the bat.

The 790i Ultra SLI supports standard JEDEC modules at 1333 MHz, or higher memory frequencies through NVIDIA’s EPP (Enhanced Performance Profiles) 2.0 spec. Boards based on vanilla 790i SLI components officially top out at 1333 MHz. Naturally, you’re going to pay more for the Ultra, so it’s important to understand a few things about running those super-fast operating modes. First, at 2000 MHz, the timings of today’s modules are in the 9-9-9 range. Second, while 790i-based boards include four memory slots, you’ll only be able to use the second and fourth slots at high speeds. It’s a slot addressing thing, NVIDIA says. Any other configuration and your board won’t boot.

Fortunately, when you have the hardware set up properly, the EPP 2.0 spec makes it easy to get up and running with the right timings at 2000 MHz. In addition, you don’t have to use extreme voltages to coax those speeds from compliant modules. Our OCZ SLI-Ready kit was comfortable at 1.9v.

Owners of NVIDIA’s 780i will notice that this chipset doesn’t use the nForce 200 companion chip, which cobbled on PCI Express 2.0 support. The 790i offers 32 lanes of PCIe 2.0 natively, comparable to the other high-end chipset in LGA775-land, Intel’s own X48 Express. Those 32 lanes are divided between a pair of x16 slots.

“But doesn’t the 790i do 3-Way SLI?”

It does. The third x16 slot is derived from the 790i MCP (the Media and Communications Processor, which you know as a south bridge). Armed with 28 lanes of PCI Express 1.1 connectivity, NVIDIA’s 790i MCP lends 16 of them in the name of more graphics horsepower.

If you do plan on using 3-Way SLI with 8800 GTX or 8800 Ultra cards, populating that third x16 slot will cost you more than just PCI Express 2.0 support. The SPP’s 32 lanes benefit from two optimizations designed to improve the efficiency of SLI—PWShort and Broadcast. The first feature enables point-to-point communication between GPUs, freeing up memory bandwidth. The second, as its name suggests, broadcasts the same data to GPUs in parallel, rather than one at a time. Both capabilities are functions of the SPP, so you don’t get them from the third slot. Fortunately, there’s always the option of going Quad-SLI using a pair of GeForce 9800 GX2 cards. The 790i does support that configuration with SLI speed-ups enabled.

Communication between the 790i SPP and 790i MCP is facilitated through a HyperTransport link with plenty of throughput for the south bridge’s copious I/O. We’d suggest that Intel take notes, but the next ICH is already expected to alleviate the narrow DMI connection currently being used.

I Believe We’ve Met

Make your way down to the 790i SLI MCP and you should start seeing some similarities to past south bridge components. Six SATA ports, one parallel IDE channel, HD Audio, dual Gigabit Ethernet controllers, 10 USB ports. Yeah. It’s the same list of features found on the 780i MCP, the 680i, and the 590i. Specifically, the 790i SLI MCP is actually a 570 SLI MCP with a new name.

Not that we’re complaining. The aging I/O controller was actually ahead of its time back in 2006 and still compares favorably to Intel’s ICH9 and AMD’s SB600. The Intel ICH only offers six PCI Express lanes, while AMD relies on its north bridges for PCIe links (granted, the 790FX swings 42 lanes of PCI Express 2.0, so the match-up is a tad skewed).

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EVGA’s 790i Ultra SLI 775 A1

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Reference, and Proud of it

Layout-wise, EVGA does a lot of things right. Passive cooling covers the SPP and MCP chipset components. EVGA includes a variable-speed fan to cool the north bridge, but it isn’t necessary (or desirable, for that matter) if you’re running at stock speeds. As we pushed the front side bus higher, adding the fan did help head off the failed benchmarks we started experiencing.

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A True Enthusiast’s BIOS

The software controlling EVGA’s nForce 790i Ultra SLI is every bit as powerful as the hardware.

Fire up into the BIOS and you’ll find a familiar list of Phoenix AwardBIOS options. Browsing down to the Advanced Chipset Options gives you the exciting stuff.

A System Clocks sub-menu lets you manually specify a CPU multiplier and whether or not you’d like to use .5x ratios. You’ll also find settings to manually tweak the PCI Express operating frequencies and SPP to MCP reference clock.

The FSB and Memory Config window handles bus speeds and timings. If you’re using EPP 2.0-compliant memory modules, you’ll see the profiles enabled. You can also choose whether to use linked or unlinked FSB and memory clocks. Or, set the option to Auto and let EVGA’s BIOS make the call. When you opt to manually key in bus speeds, the BIOS gives you a range between 400-2800 MHz for the FSB and 400-2500 for memory. Two columns tell you what the board is currently set at compared to what you’re asking it to do. Finally, a Memory Timing sub-menu facilitates further fine tuning of whichever modules you install.

As with past NVIDIA BIOSes, you can individually enable and disable processing cores. The CPU Configuration menu also lets you turn processor features on or off.

Enthusiasts who like the board’s bus speed flexibility will appreciate its highly granular voltage menu even more. You have processor voltages ranging from impossibly low to impossibly high in .00625V steps. There are front side bus options, memory voltages up to 2.275V, SPP adjustments, and MCP voltage tweaks. Progressively higher settings are color coded to indicate their aggressiveness. Newer overclockers can stay relatively safe by selecting options colored green.

Overclocking and Stability

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Overclocking the 790i

We had moderate luck overclocking our 780i SLI board from ASUS. Using an Intel Core 2 Duo E8500, we hit a 1750 MHz front side bus. That was good enough to run all of our benchmarks stably, but the board wouldn’t go any further. We dropped the chip’s multiplier, tweaked voltages, and set slower memory bus speeds—all to no avail. For all of the Striker’s fancy features and extravagant copper, its engine was capped. Our only hope was that the 790i could push us a bit further.

And push it did. We started right where we left off with the 780i and saw success. From the initial 1750 MHz setting, we inched the bus past 1830 MHz with a 9x multiplier. At the end of the day, we were looking for a solid mix of clock speed, front side bus performance, and, at NVIDIA’s recommendation, synchronous operation with the memory bus. The magic combination was 1800. At the E8500’s full 9.5x multiplier, we were able to set a synchronous 1800 MHz front side bus, 1800 MHz memory bus, and still get reliable operation at 4.28 GHz.

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SLI and Stability

We recently switched our test systems over from a single graphics card to a dual-card configuration. That way, when we run higher-resolution benchmarks, we’re more likely to see the impact of the CPUs and platforms we’re testing, rather than a brick wall as those more intense settings peg our graphics cards.

With a single GeForce 8800 GT in the 790i board, everything ran as planned. However, when we’d install a pair of the cards and set them to run in SLI mode, it’d sometimes take three or four attempts to get each benchmark to finish. Each time, the error would read, “Display driver stopped responding and has recovered.”

There are new drivers available from NVIDIA, but keep in mind that those are for the company’s newest 9-series cards. Older 8-series boards are still using the 169.25 package from December of last year. Almost certainly, the stability issues we were seeing are caused by NVIDIA’s driver software, known to have made a painful transition over to Vista.

So much for the platform concept, where devices developed under the same roof run better together.

It’s also worth noting that the latest BIOS from NVIDIA features two obliquely documented settings: P1 and P2. Apparently, they both optimize certain timing settings in the 790i SPP. We found from OCZ, though, that enabling either setting will prevent stable operation at higher memory frequencies. They should thus be left at “Auto” rather than “Enabled.”

Power and System Setup

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Power Consumption

We made the assumption that because NVIDIA’s 780i employed the nForce 200 companion chip, boards based on the platform would naturally suck down more power. It turns out that the nForce 200 doesn’t add as much to the power budget after all, though.




In fact, our ASUS Striker II Formula put out numbers very similar to the EVGA nForce790i Ultra SLI.

System Setup

Intel Core 2 Duo E8500 (3.16 GHz)

EVGA nForce 790i Ultra SLI A1 (790i Ultra SLI)
ASUS Striker II Formula (780i SLI)

2GB OCZ Technology DDR3-2000 CAS9 Memory (2x1GB) EPP 2.0
2GB OCZ Technology DDR2-1066 CAS5 Memory (2x1GB) EPP 1.0

2 x EVGA GeForce 8800 GT in SLI

Seagate Barracuda 7200.11 1TB SATA 3 Gbps Hard Drive

Windows Vista x32 Service Pack 1, current as of April 5th, 2008 with Windows Update

DirectX 10

Desktop resolution 1600x1200, 32-bit color, 85Hz refresh

We disable Vista’s UAC and generate an image using Norton Ghost 11 to create the same basic benchmark platform for each test bed. The image is frozen with the latest Windows Updates and deployed to each system. The appropriate drivers are then loaded to the machines.

We tested the 790i in a couple of different configurations. First, we used the EPP 2.0 profile of our OCZ modules to test performance with high-speed memory. Then, we dropped the modules to 1333 MHz to see how things changed at synchronous settings and lower latencies. The overclocked configuration is included, of course, as are the 780i comparison numbers running EPP 1.0 memory modules.

Benchmarks

SiSoft Sandra
3DMark06
Unreal Tournament III
Crysis
Lost Planet: Extreme Condition
Half-Life 2: Episode 2
Company of Heroes
PCMark Vantage
Windows Media Encoder
HDTach

SiSoft Sandra Memory

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Memory Bandwidth

Notes

The first thing we wanted to check was how 2000 MHz memory affected the 790i’s peak bandwidth versus its predecessor. It turns out that the 2000 MHz DDR3 configuration is able to buy a couple hundred MBps over DDR2 running at 1066 MHz. The different isn’t enormous, though.

More interesting is how the 2000 MHz setting compares to DDR3 running at 1333 MHz—synchronous with our Core 2 Duo E8500. The synchronous setting is actually faster, aided in part by lower latency settings at that more conservative frequency.

Then there’s the overclocked configuration to look at, where we set the front side bus and memory bus to 1800 MHz. From 7.5 GBps to 8.5 GBps—not bad at all.

3DMark06

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3DMark06

Notes

We didn’t expect the processor performance numbers to change much as we swapped out motherboards and reconfigured memory. But the 3DMark06 processor test definitely shows what overclocking can do for a 790i machine.

The overall scores were interesting as well. Most notably, the 790i setup running 2000 MHz memory was outperformed by the ASUS-based 780i configuration. On top of that, the 1333 MHz synchronous setup proved faster than the 2000 MHz mode. And of course, at 4.3 GHz, the 790i and Core 2 Duo combo takes no prisoners.

Unreal Tournament III

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Unreal Tournament III

Notes

We used the botmatch technique for benchmarking Unreal Tournament, populating our map with 24 characters, 12 to a side.

With a solid idea of how our various setups fared against each other in a synthetic metric, we fired up Unreal Tournament III for a round of testing. Interestingly, there really wasn’t much variance from the 780i to the 790i, even at 800x600. Overclocking bought the 4.3 GHz setup a few extra frames, but that was about it.

The spread remained fairly even at 1280x1024 and changed only slightly at 1600x1200, where the 790i started inching ahead. If you have a capable graphics solution, overclocking is going to buy additional performance especially at 1600x1200.

Crysis

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Crysis

Notes:

We ditched the baked benchmarks for this test, recorded our own timedemo, and used it instead. Unfortunately, Crysis turns off the AI when you’re playing back demos, so you can expect actual game play to better tax these chips.

The 790i manages to pick up a few frames against the 780i at both 800x600 and 1280x1024. Of course, at 800x600, the overclocked Core 2 Duo puts down the best numbers. It then does the same at 1280x1024.

That tweaked setup’s best performance happens at 1600x1200 though, where it breaks the 50 fps barrier. The next best performing solution is the 790i running a 1333 MHz front side bus and synchronous memory.

Lost Planet

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Lost Planet: Extreme Condition

Notes:

We used all of the DirectX 10 settings for our Lost Planet testing. But while we’ve seen graphics bottleneck after graphics bottleneck in the past, loading up a pair of 8800 GTs helps alleviate that particular subsystem…at least at 800x600. At low res, both 790i-based configurations outpace the older 780i.

Once you hit 1280x1024, it’s easy to get the impression we’re being held back by something, yet again. Considering there’s no difference between the radically overclocked setup and the stock configs, it’s a good bet that the problem isn’t with processing power or memory bandwidth. Hello, graphics bottleneck?

Bumping the setting up to 1600x1200 demonstrates a similar situation, whereby all four setups get stuck in the 50 fps range. Even still, that’s a significant improvement over the numbers we were seeing with a single Radeon HD 3780. This one is just extremely graphics-limited.

Half-Life 2

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Half-Life 2: Episode 2

Notes

Half-Life 2 has always seemed to give processors and platforms a little more room to stretch than some of the other heavily graphics-intensive games in our test suite. Here we see our custom timedemo test favor the overclocked config across the board.

The 780i-based setup manages to hold its own each step of the way, consistently edging out our 790i system running 2000 MHz memory. When everything’s synced up at 1333 MHz, however, the 790i slips ahead. Is it enough to justify a $350 board and expensive memory? We’d be inclined to say no.

Company of Heroes

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Company of Heroes

Notes

Here’s another title adapted for DirectX 10 support with a serious emphasis on graphics performance. Back when we used to run a single Radeon HD 3780, we’d see a range of results at 800x600, a tighter pack at 1280x1024, and parity at 1600x1200, where processor performance didn’t matter as much compared to graphics horsepower.

Now it’s straight lines across the board. At 800x600, 1280x1024, and 1600x1200, we have enough processing power and ample graphics muscle to bump up against the imposed vsync limit at any combination of settings.

PCMark Vantage

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PCMark Vantage

Notes

PCMark Vantage is the latest synthetic system metric from Futuremark based on a number of real-world workloads. The benchmark is thread-aware and comprised of several test suites that measure performance under Windows Vista.

If there wasn’t a consistent performance increase going from 780i to 790i in our gaming tests, you can certainly see one in here in Vantage overall score. We again see the setup running synchronous 1333/1333 MHz bus speeds churning out the highest numbers. Actually, that’s not entirely true—the overclocked setup performed even better.

Individual components of Vantage tell their own tales. For the most part, though, results are fairly consistent. In tests that tax platform components, the 790i does a bit better than the NVIDIA chipset before it.

Windows Media Encoder 9

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Windows Media Encoder 9

Notes

It’s no surprise that the 4.3 GHz 790i-based machine throws down the fastest Windows Media encoding time. However, it is interesting that the configurations with 2000 MHz memory and 1333 MHz memory perform similarly, both beating the 780i machine by two seconds.

USB File Transfer Speed

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500MB Folder of Misc. Files

Notes

There’s not much to see here. No matter how we set up the 780i and 790i, our 500MB transfer to an external Maxtor hard drive took a consistent 37 seconds.

HDTach

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HDTach

Notes

Again, not a ton of variance in how these setups perform. The overclocked configuration did demonstrate higher CPU utilization numbers than any of the other setups, but only by a couple of percent. Burst speeds and average read speeds were fairly even down the line.

Ballistics Report: EVGA 790i Ultra SLI A1 Motherboard

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Pros:

3-Way and Quad SLI: When it comes to graphics performance, NVIDIA holds the top spot. And if you want to double, triple, or even quadruple the potential of your graphics subsystem, the 790i is one of your only options on the Intel side of things.

Scalability: The nForce 780i SLI chipset wasn’t a bad overclocker, but it also wouldn’t let us take our Core 2 Duo E8500 as far as we knew it’d go. This EVGA 790i Ultra SLI motherboard does. Using stock Intel air cooling, we were able to achieve a 4.3 GHz core clock using an 1800 MHz front side bus and memory running synchronously at 1800 MHz.

Enthusiast Allure: From the onboard power/reset buttons to the two-digit diagnostic readout to the attractive color scheme to the loaded BIOS, EVGA wisely tailored this $350 premium product to the enthusiast community. As a result, it’s easy to work on, easy to adjust, and easy to like.

Features, Features, Features: The nForce 790i chipset by itself is a feature-rich platform. This board adds onto that, though, with extra SATA connectivity, FireWire, optical/coaxial audio output, and a beefy cooling solution.

Cons:

Price: No doubt about it; $350 for a motherboard is asking a lot. When you add on to that the DDR3 memory requirement and its associated price premium, it gets hard to justify the extra expense for what minimal performance gain the 790i Ultra SLI enables. This is undoubtedly a solution for enthusiasts unconstrained by a budget and looking for serious overclocking and SLI support.

Stability: Despite the lip service NVIDIA’s nForce 790i Ultra SLI seems to be receiving for its stability, our experiences run to the contrary. With a single GeForce 8800 GT installed, there were no problems. Add a second, mix in NVIDIA’s ForceWare 169 drivers, and we were left with unexplainable driver freezes that’d boot us back to the desktop. Unfortunately, the 174s don’t work with the 8800 GT, either.

Final Verdict

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EVGA nForce 790i Ultra SLI

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