GeForce 9800 GTX and 3-way SLI: May the nForce Be With You
by Derek Wilson on April 1, 2008 9:00 AM EST- Posted in
- GPUs
The Test
Once again we used the Skulltrail system for most of our comparisons. We’ve added on the 790i board for 3-way SLI performance scaling tests.
I didn’t believe I would be saying this so soon, but our experience with 790i and SLI has been much much worse than on Skulltrail. We were plagued by power failure after power failure. With three 9800 GTX cards plugged in, the system never got up over 400 W when booting into windows, but after a few minutes the power would just flicker and cut out.
It didn’t make sense that it was the PSU size, because it wasn’t even being loaded. We did try augmenting the PSU with a second one to run one of the cards, but that didn’t work out either. The story is really long and arduous and for some reason involved the Power of the Dark Side, but our solution (after much effort) was to use one power supply for the system and graphics cards and one power supply for the drives and fans. Each PSU needed to be plugged into its own surge protector and needed to be on different breakers.
The working theory is that power here isn’t very clean, and the 790i board is more sensitive to fluctuations in the quality of the power supplied (which is certainly affected by the AC source). Isolating breakers and using surge protectors was the best we could do, and we are very thankful it worked out. It seems likely that a good quality 1000-1500 VA UPS would have been enough to provide cleaner power and solve the issue, but we didn’t have one to test with.
Once we handled this we were mostly able to benchmark. We could get a good 15 minutes of up time out of the system, but after repeated benchmarking instability crept back in and we’d need to wait a while before we tried again. The majority of these problems were on 3-way and Quad SLI, but we did have a hiccup with a two card SLI configuration as well. We didn’t have any trouble at all with single card solutions (even single 9800 GX2 solutions).
Before anyone says heat, we were testing in an open air environment in a room with an ambient temp of about 15 degrees C, with one 120mm fan blowing straight into the back of the GPUs and another blowing through the memory (we did take care not to interfere with the CPU HSF airflow as well). The graphics cards did get warm, but if heat was the issue here, I’d better get a bath of LN2 to run this thing submerged in ready.
It is very important that we note one more time that this is the C0 engineering sample stepping and that NVIDIA explicitly told us that stability might be an issue in some situations. The retail C1 stepping should not have these issues.
Here’s our test setup:
| Test Setup | |
| CPU | 2x Intel Core 2 Extreme
QX9775 @ 3.20GHz |
| Motherboard | Intel D5400XS (Skulltrail) |
| Video Cards | ATI Radeon HD 3870
x2 NVIDIA GeForce 8800 Ultra NVIDIA GeForce 9800 GTX NVIDIA GeForce 9800 GX2 |
| Video Drivers | Catalyst 8.3 ForceWare 174.74 |
| Hard Drive | Seagate 7200.9 120GB 8MB 7200RPM |
| RAM | 2xMicron 2GB FB-DIMM DDR2-8800 |
| Operating System | Windows Vista Ultimate
64-bit SP1 |
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7Enigma - Tuesday, April 1, 2008 - link
NM, the images now show up that include the 8800GT. Thanks! So it seems the 9800GTX in most situations is <20% faster than the 8800GT at 1280X1024 correct? Since I game on a 19" LCD I might be better off with an 8800GT for a year or so and then upgrading to the next round of cards.....decisions....decisions....For anyone that cares here's a direct comparison using the numbers from the table:
9800GTX compared to 8800GT at 1280X1024 resolution
Crysis.....19.5% faster
CoD4.......17.5-18.5% faster (depending on no/4X AA)
Oblivion...17.5-27% faster (depending on no/4X AA)
QuakeW.....10.5% faster
Stalker....13% faster
just4U - Tuesday, April 1, 2008 - link
So it's roughly 2% faster then the GTS/512? :(7Enigma - Tuesday, April 1, 2008 - link
Again I'm disappointed that this review completely fails to include the 8800GTS. I asked in the previous 9800GX2 review as did several others and there was no response to the questions. It definitely appears that they are purposely failing to include the most obvious competitor to the 9800GTX (and any future lower-end cards, GTS, GT, etc.).Looks like I'll be going to another site for a better comparison.
7Enigma - Tuesday, April 1, 2008 - link
Hocp has a good comparison review (albeit with their odd way of benchmarking) of the 8800GTX/S against the 9800GTX. Pretty much shows what we thought, some slight improvements, but nothing to write home about. This quote from the conclusion sums up the release of the 9800GTX:"If you are a gamer and were hoping to upgrade, today is not the day if you already own pretty much any 8800 series card. Here’s hoping real next-gen technology will be seen in a “9900” series soon."
This pretty much solidifies my purchase of an 8800GT. I just can't see the advantage of shelling out closer to $300 for a slightly better card than a $200 8800GT, with the hopes that within a year SOMEONE comes to the rescue of actually releasing a next gen card that is better than the current/previous generation.
AggressorPrime - Tuesday, April 1, 2008 - link
I'm pretty sure dual, tri, and quad Crossfire is not supposed to give the exact same results in Crysis. There must be something wrong with the chart.AggressorPrime - Tuesday, April 1, 2008 - link
It looks like these tests are done with the 790i, yet there is no info on what RAM is used or motherboard for that matter in the chart.It is interesting that a 790i setup would beat Skulltrail in Crysis, but I guess fast RAM is more important.
Noya - Tuesday, April 1, 2008 - link
...the best bang for the buck is a pair of 8800gt in SLI @ about $350.KingViper - Tuesday, April 1, 2008 - link
Can we get a spell check in the house?jtleon - Tuesday, April 1, 2008 - link
DittoDittoDittoIjusthateitwhenwebcontentisnotedited!!!!Regardsjtleon
JarredWalton - Tuesday, April 1, 2008 - link
Fixed.