NVIDIA Single Card, Multi-GPU: GeForce 7950 GX2
by Derek Wilson on June 5, 2006 12:00 PM EST- Posted in
- GPUs
Introduction
Today marks the launch of the first GPU maker sanctioned single card / multi-GPU solution for the consumer market in quite some time. Not since Quantum3D introduced the Obsidian X24 have we seen such a beast (which, interestingly enough, did actual Scan Line Interleaving on a single card). This time around NVIDIA's flavor of SLI and PCIe are being used to connect two boards together for a full featured multi-GPU solution that works like a single card as far as the end user is concerned. No special motherboard is required, the upcoming 90 series driver will support the card, and there is future potential for DIY quad SLI. There is still a ways to go until NVIDIA releases drivers that will support quad SLI without the help of a system vendor, but they are working on it.
For now, we will take a look at the card and its intended use: a card using a single PCIe connection designed to be the fastest NVIDIA graphics board available. While there are some drawbacks of SLI still associated with the 7950 GX2 (certain games scale less than others), the major issues are quite nicely resolved: there is no need for an SLI motherboard, and it's much easier to make sure everything is hooked up correctly (with only one power connector, no SLI bridge needed, and only one card to plug in). The drivers start up and automatically configure support for multi-GPU rendering, and (after our motherboard's BIOS was flashed) we had no problem with the system recognizing the new technology.
While the potential for quad SLI is a reality, the usefulness is still fairly limited - only users with ultrahigh resolution monitors will see the benefits of four GPUs. At lower resolutions, CPU overhead becomes a factor, and some limitations of DX9 come into play. We certainly want to test quad SLI on the 7950 GX2, but we will have to wait until we get the equipment together and track down a driver that will support it. In this article, we will compare the 7950 GX2 with other high end NVIDIA and ATI cards, and we'll also take a look at how well it scales compared to it's close relative: the 7900 GT / 7900 GT SLI. But before we get to the benchmarks, let's take a look at how NVIDIA puts it all together in a way that avoids the necessity of an SLI motherboard or an external power supply.
Today marks the launch of the first GPU maker sanctioned single card / multi-GPU solution for the consumer market in quite some time. Not since Quantum3D introduced the Obsidian X24 have we seen such a beast (which, interestingly enough, did actual Scan Line Interleaving on a single card). This time around NVIDIA's flavor of SLI and PCIe are being used to connect two boards together for a full featured multi-GPU solution that works like a single card as far as the end user is concerned. No special motherboard is required, the upcoming 90 series driver will support the card, and there is future potential for DIY quad SLI. There is still a ways to go until NVIDIA releases drivers that will support quad SLI without the help of a system vendor, but they are working on it.
For now, we will take a look at the card and its intended use: a card using a single PCIe connection designed to be the fastest NVIDIA graphics board available. While there are some drawbacks of SLI still associated with the 7950 GX2 (certain games scale less than others), the major issues are quite nicely resolved: there is no need for an SLI motherboard, and it's much easier to make sure everything is hooked up correctly (with only one power connector, no SLI bridge needed, and only one card to plug in). The drivers start up and automatically configure support for multi-GPU rendering, and (after our motherboard's BIOS was flashed) we had no problem with the system recognizing the new technology.
While the potential for quad SLI is a reality, the usefulness is still fairly limited - only users with ultrahigh resolution monitors will see the benefits of four GPUs. At lower resolutions, CPU overhead becomes a factor, and some limitations of DX9 come into play. We certainly want to test quad SLI on the 7950 GX2, but we will have to wait until we get the equipment together and track down a driver that will support it. In this article, we will compare the 7950 GX2 with other high end NVIDIA and ATI cards, and we'll also take a look at how well it scales compared to it's close relative: the 7900 GT / 7900 GT SLI. But before we get to the benchmarks, let's take a look at how NVIDIA puts it all together in a way that avoids the necessity of an SLI motherboard or an external power supply.
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bluebob950 - Tuesday, June 27, 2006 - link
thinking about getting a 7950 but i cant find monitor any monitors that do 2048 my boss says the dell 21" at work do but i have yet to see it what do you use? and where can i find them online?bluebob950 - Tuesday, June 27, 2006 - link
thinking about getting a 7950gt but i cant find monitor any monitors that do 2048 my boss says the dell 21" at work do but i have yet to see it what do you use? and where can i find them online?JNo - Wednesday, June 7, 2006 - link
I think the review at Hexus.net bares a very interesting negative conclusion, somewhat in contrast to anandtech (not that I'm dissing anandtech), and provides food for sobering thought...http://lifestyle.hexus.net/content/item.php?item=5...">http://lifestyle.hexus.net/content/item.php?item=5...
Think seriously about what's been presented to you in this article thus far, concerning GeForce 7950 GX2, and you should (if I can do my job properly) come to a conclusion like this: NVIDIA GeForce 7950 GX2 is probably the most caveat-laden graphics purchase yet released.
The conditions that have to be satisfied before it makes sense to get one are pretty much as follows:
* Are you willing to live with less-than-absolute best image quality from the high-end generation right now?
* Are you sure the games you play all have SLI support, or you're at least happy to wait for support to come in a future driver?
* Do you have a PC platform that supports it properly, which is realistically just nForce SLI of some flavour?
* Do you have a very well ventilated PC chassis, able to assist in the significant cooling challenges it presents?
* Do you own a high resolution PC display, since it's built for at least 1600x1200 in current supported games?
* If you run dual displays, are you happy for one to go blank when in multi-GPU mode?
Be sure and really consider the first two questions, and ponder the fact that ATI Crossfire is arguably even worse at satisfying the second, given its lack of a user-adjustable game profiling system. Done so? Good.
Now given yes to all of the above, are you then willing to spend £450 on a single graphics board? You are? Brilliant, they're available today, you'll enjoy the framerates and overall IQ, happy shopping!
Tephlon - Wednesday, June 7, 2006 - link
I just wanted to point out... that list isn't just particular to this card. That's all SLI setups.All have to watch the heat. Drivers don't allow any SLI setup to dual-view+multi-GPU. SLI does dominate primarily in Hi-Res configs. and so on and so on.
Its still a great list to consider... but please remember that it isn't limited to just the 7950GX2.
DerekWilson - Wednesday, June 7, 2006 - link
except the 3rd point doesn't apply at all to 7950 GX2 -- It seems there has been a lot of confusion around the support requied for this card. It will run on Intel, ATI, VIA, SiS, an NVIDIA chipsets as long as the BIOS supports non-video devices in x16 PCIe slots along with supporting add-in PCIe switches. Suprisingly many boards support these features as of this week.the 7950 has a bunch of advantages over a 7900 GT SLI setup, not the least of which is performance. The lenient platform requirements, power draw less than an x1900xt, potential for expansion to quad sli, and it's really very transparently plug and play (just plug it in, install drivers, and no more tweaking is required for it to work as expected).
Jeff7181 - Tuesday, June 6, 2006 - link
On page three in the chart it says the 7900GTX core clock is 700 MHz (650 for vertex core). Is that accurate? So what I'm seeing and adjusting in the driver settings with coolbits is actually the speed of the vertex core?DerekWilson - Tuesday, June 6, 2006 - link
you know, I borrowed that chard from NVIDIA's reviewers guide on the 7950 GX2 ...I am under the impression that the vertex core of the 7900 GTX is 700MHz. As this is NVIDIA's chart, I'm not sure if vertex clock is listed first or second ...
Jeff7181 - Tuesday, June 6, 2006 - link
Based on the other values in the chart, and the row/column titles, I assumed the number given was supposed to be the core clock, and the one in parenthasis was supposed to be the vertex clock. I guess it could be a type-o... otherwise I want a new 7900GTX since the core speed of mine is only 650 MHz and it should be 700 according to that chart. :Dv12 - Tuesday, June 6, 2006 - link
Could you post comparative scores of the X1900XTX as well? does it beat the 7950 or not? I cant tell from this review.V12
AnnonymousCoward - Tuesday, June 6, 2006 - link
Thanks for the sweet article. 2 GPUs on a non-SLI board is the way to go...until dual-core GPUs. When are those coming out, anyway?