Review: Geforce 9800GX2 is super fast
Geforce 9800 GX2 is the first complete high-end card, at least that's how Nvidia describes it in its own words. Let's not look back at all the shortcomings of the 8800 Ultra, but take a peak at what the 9800 GX2 has to offer. This is the fastest graphics card ever made, but in fact it's two graphics cards stapled together. Nvidia will probably say that the 9800 GX2 combines the power of two 9800 GPUs with a grand total of 256 stream processors and an earth shuddering 1GB frame buffer (512MB per core). Obviously, the card is a dual slot design and it looks sexy, but also elegant, as it is encased in an all metal body.
A picture of the reference card (above) and Gainward's card (below).
The combined power of two GPUs is not the only good thing about this card. Pure Video HD technology, first seen on G92 based cards, is now an integral part of the package and that's one of the reasons Nvidia calls its new flagship a complete solution, as it gets you top notch performance as well as multimedia capabilities.
The complete package looks robust and sturdy. The fan is inside the metal case and there's no way you can damage it, or any other part of the card, for that matter.
Its GPU duet works, thanks to new SLI technology. The driver manages them by using 4-way alternate frame rendering (AFR), and scaling is easy. It's also possible to use two 9800 GX2 cards in a Quad-SLI setup.
ATI managed to do pretty much the same thing with its HD3870 X2 card, but it used just one PCB. Nvidia took another approach and it's still using two PCBs.
You can see how the GPUs are mounted on the picture above, each on its own PCB facing the other. This allowed the engineers to squeeze the cooler in between, sandwiched between the two PCBs. The fan scoops up cold air through the sides and the rear of the card and forces it through the card. Most of the hot air exits the card on top and if you haven't got some serious airflow in the your chassis, this might be an issue. The card can withstand temperatures of up to 105°C, although we doubt that it will ever get that hot. If you somehow manage to push it so hard and reach this temperature, it will automatically downclock to reduce heating, and if that doesn't turn out to be enough, it will just shut down to prevent failure. During our test we measured 81°C under load and 68°C in idle.
The 65nm GPUs have 1508 million transistors in total, if we combine them. They are clocked at 600MHz with a Shader clock of 1500MHz and these numbers are similar to those we already saw on 8800 GT cards. It has a total of 256 stream processors (128 per GPU). The memory is clocked slightly higher than on previously seen G92 cards. Geforce 9800 GX2 uses memory clocked at 1000MHz, slightly more than the 900MHz and 970MHz seen on the 8800 GT and GTS, respectively. The memory bus is 256-bit and the card packs 2x512MB of GDDR3 memory.
A look at the top of the card shows where the power connectors are hidden. With the new cooler design even the SLI and SPDIF connectors have small caps, which protect them and help the card look a bit more elegant.
According to the specs the card should consume more than 197W and Nvidia recommends a 580W PSU for a single card configuration and an 850W PSU for a dual card SLI setup.
Be sure to check if your PSU has an 8-pin PCIE power connector, as you will need it as well as a 6-pin connector. It sounds funny, but some 8-pin connectors won't fit into the connector on the card and Nvidia suggests you push them in using force. Don't push your luck with such a pricey piece of hardware. It's much better to cut off a piece of plastic on the connector. This problem will soon be fixed by PSU manufacturers who caused it in the first place by not sticking to the specifications.
HybridPower technology is a novelty which we already saw in action and we liked the idea very much. It allows the card to power down when we're not using demanding 3D applications. Of course, at the moment this only works with the 780a high-end AMD chipset with integrated graphics. Intel versions should appear in Q2.
This lets us save a lot of power and you can get a general idea of how it works on the slide above. When we don't need a discrete GPU, Nvidia's integrated graphics kick in and help us reduce power consumption. It will for 2D, undemanding 3D or watching HD video. We saw HybridPower in action at CeBIT, but it was necessary to shut down the 9800 GX2 manually. We're assuming that this action is now controlled automatically. HybridPower will be a feature of all upcoming Nvidia chipsets.
At the back we've got two DVI connectors as well as one HDMI. You no longer get an HDMI converter in the box, since HDMI is now an integral part of the reference design. An SPDIF cable is still necessary to channel sound through the card to the HDMI connector and you'll get it in the box.
You can see the tiny holes above the HDMI connector. These are, in fact, LEDs, used to show you which state the card is in. The DVI connector which should be used for your main display is marked with a 1. We didn't try to connect three displays using the HDMI out, but we will get around to it sooner or later.
Here's the layout of the connectors, borrowed from Nvidia.
Of course, the card uses PCI Express 2.0, supports Vista, or should we say, DirectX 10.
You already saw that the card has a single SLI connector and this means you can use it in a Quad-SLI setup, but not in Tri-SLI. Quad-SLI works well and it will be launched any day now. We saw it scale well using two 9800 GX2 cards. In order to make this possible, Nvidia turned to 4x AFR (Alternate Frame Rendering). This means that it can render 4 frames simultaneously, but this depends on OS framework support ,which we currently have only in Vista.
Gainward uses its standard packaging, and we already saw that it ships with an SPDIF cable. You'll also get Tomb Raider Anniversary with it.