Morphing nForce4 Ultra into nForce4 SLI
by Wesley Fink on January 18, 2005 7:30 AM EST- Posted in
- CPUs
Performance: x16 vs. x16/x2 vs. x8/x8 (SLI)
The best way to verify the success of the mod was to run benchmarks. We had already done extensive testing of SLI performance in Anand's NVIDIA's GeForce 6 SLI: Demolishing Performance Barriers. To get right to the point, we tested the Ultra modded to SLI with Half Life 2, Doom 3, and Far Cry at both 1280x1024 and 1600x1200. We also benchmarked at both settings with and without the eye candy - since Anti-Aliasing and Anisotropic Filtering can exact a large hit on a single GPU.We were interested to see exactly what performance you could get with two video cards on the Ultra board before the mod to SLI, so we also ran benchmarks of the performance of x16/X2 Ultra dual-video card mode.
All tests were run on a DFI LANParty UT nF4 Ultra-D and a DFI LANParty nF4 SLI-DR. We first confirmed that test results were the same on the LANParty UT modified to SLI and the LANParty nF4 SLI, which is a native SLI chipset board. There was no difference in performance after the SLI modification to the Ultra chipset, so results are reported as SLI and relevant to either SLI or Ultra modified to SLI.
Video cards were a single MSI 6800 Ultra PCIe or a matched pair of MSI 6800 Ultra in SLI and x16/x2 modes. Memory in all benchmarks was OCZ 3200 Platinum Rev. 2 (Samsung TCCD) at 2-2-2-10 timings. The CPU was an Athlon 64 4000+, and the power supply was an OCZ PowerStream 600.
In the course of testing, we found that we could actually run the x16/x2 mode on either the SLI board or the Ultra board by leaving the jumpers in normal mode, using an SLI bridge across the two video cards, and enabling SLI in the nVidia driver. Results on the SLI board in x16/x2 mode were, as expected, the same on the nF4 Ultra board as shipped or the Ultra after SLI modification. The one huge advantage of the SLI-mod was that once we had SLI-modded the Ultra chip, we could run x16/x2 mode with any nVidia Forceware driver up to 70.xx. The 70.90 driver was the highest driver to support x16/x2 mode even with an SLI chip. x16/x2 would not run, however, with the most recent 71.xx drivers. 71.xx drivers report the board to be SLI-capable, but it does not recognize the second card as an appropriate card for SLI. Clearly, nVidia must have turned off x16/x2 support in the most recent driver as well, only allowing their specified x8/x8 mode to work. We suspect that enthusiasts will find a way to correct this very quickly.
UPDATE: The Gigabyte 3D1 is a single video card with two 6600GT GPUs. It will only work in x8/x8 (nVidia) SLI mode on a Gigabyte SLI board. However, we did find the 3D1 will operate in x16/x2 mode on both DFI boards with jumpers in "normal" position. We have added test results to our charts with both single 6600GT and x16/x2 dual video mode with the 3D1. The Gigabyte 3D1 provides the interesting possibility of a form of SLI performance on single x16-slot Ultra boards with the SLI mod.
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PrinceGaz - Friday, January 21, 2005 - link
What gets me is that SLI is still viewed by so many people as a "cheap upgrade path" for their graphics later on, and they use that to justify and SLI (or possibly a modded Ultra board).Has everyone who comments here forgotten that there is the option of selling your 6600GT when you fancy an upgrade, and buying a second-hand 6800GT to replace it? I think you'd find the upgrade cost from the 6600GT to 6800GT would be less than a new 6600GT would cost you, regardless of how much prices on new cards fall. The 6800GT will also outperform two 6600GTs in almost all games, especially at higher resolutions and quality settings.
Even if the second-hand price difference between the 6600GT you want to sell, and the 6800GT you'd want to buy isn't smaller than the cost of a new 6600GT; there's still the question of what are you going to do with two outdated 6600GTs when it's time to do a proper upgrade. Single 6600GT cards will be going dirt cheap because they'll be considered low-end, and nobody would buy two of them when much better single card solutions are available. A 6800GT will at least have some reasonable second-hand value still.
The only possible reason for seeing SLI as a viable upgrade option is if you're afraid of buying or selling stuff second-hand. In that case you're missing out on a lot of bargains.
SLI should only be considered by people buying 6800's, either both of them at once or the second within a few months. Considering the cost involved, they'd be fools to save a few dollars and hope the Ultra->SLI mobo hack works correctly for them.
crash - Friday, January 21, 2005 - link
#73 and it will all be moot because you won't have the bridge connector. You will either have to make your own or buy one from someone else. Either way, the cost will reach or exceed what you would've spent had you purchased the SLI board in the first place.AtaStrumf - Friday, January 21, 2005 - link
Some people still don't get the point of SLi. It's in the cheap, gradual upgrade path.This hack, if nVidia doesn't disable it -- driver support in case of SLi is extremely important - new games will require new drivers!!!, makes this an even better deal for the cheap bastards among us, because you only pay a slight premium for being able to cheaply uprage later on (66(8)00GT will be much cheaper when I buy a second one) instead of having to first cash out big time for an SLi mobo just to get into the SLi game.
MarkM - Thursday, January 20, 2005 - link
#65, #66 - what is wrong with nVidia marketing different performance levels. Why do you feel you need to single them out for your wrath? Do you think the CD/DVD for Microsoft's OfficePro costs any more to burn than the one for their OfficeStanderd? Do you get mad at AMD preventing you from increasing the multiplier on their A64 chips?Sheez, it's a common buriness practice, everyone does it. If it let them lower their unit cost by producing both chipsets on the same line instead of needing different ones, then bully for them.
ChineseDemocracyGNR - Thursday, January 20, 2005 - link
#63, I don't think you will be able to buy the 3D1 card without Gigabyte's SLI motherboard.I have two comments:
1) in your future benchmarks of SLI products could you add some games that may not have been optimized by nVidia? I don't think most people know about this: http://www.pcper.com/article.php?aid=99&type=e...
2) Maybe the nForce4 and nForce4-4X can be modded to add SATAII and the other features of the Ultra chipset?
bupkus - Thursday, January 20, 2005 - link
#69 - My only suggestion is if you see the SLI board price as just too high for the initial introduction, the price drop over the next year will subsidise your next upgrade assuming it will be atleast a year until you go for a new video card. Of course what will be is just a guess.OriginalReaper - Thursday, January 20, 2005 - link
It's already $800-1000 on the 2x GPUs, I think spending a little extra for a the nV SLI x8/x8 is worth it over the Ultra SLI.Not that I'd want either solution at the moment.
bupkus - Thursday, January 20, 2005 - link
Consider also, you can buy an SLI capable display adapter today with a non-SLI motherboard. In a year when you may want to upgrade your video by buying a twin you may also be considering a new, dual core CPU.Live - Thursday, January 20, 2005 - link
To all of you who does not see the point of this mod:The point as I see it is not to buy 2 * 400$ cards and then skimp on the motherboard. This is for the ones who can’t afford SLI today. Buy this motherboard and your SLI ready if and when cheaper cards are out or your preferences/financial situation changes.
I'm one of those people that hold on to my parts for at least 2 years. So it’s nice to know I have as many options in the future open to me with a board like this.
My bet is that SLI with dual core CPUs and games that are multithreaded and SLI ready from the get go like perhaps Unreal 3 or Far Cry 2 will make SLI look rather tempting.
Imagine playing Duke Nukem Forever which will come ...heh never mind ;)
bupkus - Thursday, January 20, 2005 - link
#65 - Tell nVidia to "stuff it" and wait for the X800XL. Look people, we all did just fine before SLI and we can do fine without it. Corporations just love it when we are so convinced that we need something they sell that we call them names for taking advantage. Just don't buy into it.