Nvidia GeForce GTX 200: Power Consumption, Thermals, Acoustics and Compatibility
Nvidia continues to recommend using high-capacity power supply units for their graphics accelerators. However, as we have already proven multiple times any 400W-450W PSU will be sufficient to ensure their normal operation. They claim that the new Nvidia GeForce GTX 280 solution has peak power consumption of 236W, however, in order to find out how this number correlates with the actual power consumption, we took some standard measurements using a special testbed:
- AMD Athlon 64 FX-55 CPU (2.6GHz)
- EPoX EP9-NPA+ SLI mainboard (Nvidia nForce4 SLI)
- PC3200 (2x512MB, 200MHz)
- Western Digital Raptor WD360ADFD HDD (36GB, SATA-150, 16MB buffer)
- Chieftec ATX-410-212 PSU (410W)
- Microsoft Windows Vista Ultimate 32-bit
- Futuremark PCMark05 Build 1.2.0
- Futuremark 3DMark06 Build 1.1.0
The 3D load was created by running the first SM3.0/HDR test from 3DMark06 in a loop at 1600x1200 with forced 4x FSAA and 16x AF. This test is known to load the GPU beautifully, even though it may be somewhat obsolete for the contemporary technical standards. It suits better than 3DMark vantage tests. The Peak 2D load is emulated by means of the 2D Transparent Windows test from PCMark05. This benchmark is pretty acute because it emulates active work with windows and Windows Vista Aero uses 3D, as we all know. We may replace it with a more popular HD video playback test later on.
This test session produced the following results:
As usual, the developer’s numbers turned out way higher. And impeccable operation of the new Nvidia flagship solution on our testbed equipped with a modest 410W PSU proves it.
Of course, Nvidia GeForce GTX 280 boasts pretty serious peak power consumption. However, it not only failed to reach 200W, but never even caught up with Nvidia GeForce 9800 GX2. Nvidia GeForce GTX 260 also demonstrated pretty ordinary power consumption readings: the maximum was only 136W, which is only 6W more than the power consumption of its closest competitor – ATI Radeon HD 4870.
We have to point out that the use of an 8-pin power connector for the top model is absolutely justified: it does receive much more than 75W, which is the maximum allowed workload for a 6-pin connector. Although in 2D mode the new cards drop their GPU frequency to 100MHz and lower the memory frequency significantly, too, they are not very economical in this mode: 65nm process and extremely complex design of the new G200 series chips do their job here. However, ATI Radeon HD 4870 wouldn’t be economical in a similar situation either, although it supports advanced ATI PowerPlay technology.
It is interesting that the Nvidia GeForce GTX 280 power consumption measurements in fact prove that ATI picked the right strategy by betting on multi-processor solutions for the high-end segment. As you know, Nvidia GeForce 9800 GX2 has two G92 GPUs onboard that gives it 256 shader processors, 128 texturing processors, and 32 RBE. In other words, it boasts potentially higher computational and texturing performance than Nvidia GeForce GTX 280 at the same level of power consumption. Anyway, we will b able to capitally impeach or acquit the idea of creating powerful monolithic GPUs for the high-end segment only after we complete our tests in real gaming applications.
The thermal conditions of the new family turned out surprisingly mild: in idle mode the GPUs of both graphics cards heated up only to 45-46ºC, which they certainly owe to the highly efficient cooling system. This system worked perfectly well in 3D mode keeping the GPU temperature around 68-70ºC for Nvidia GeForce GTX 260 and no higher than 72ºC for Nvidia GeForce GTX 280. It is a truly excellent result, however, the price you have to pay for it is the higher level of generated noise. The readings from our Velleman DVM1326 noise-meter were as follows:
The cooling system runs pretty quietly in 2D mode, almost as quietly as the best VGA coolers out there including the ones used on previous generation Nvidia solutions. However once the workload increases, the situation changes dramatically. Nvidia GeForce GTX 280 turns out as noisy as GeForce 9800 GX2, which is not surprising considering its high power consumption. And most noise comes not from the fan motor, but from the airflow hissing through the heatsink. The less powerful Nvidia GeForce GTX 260 is quieter under high workload, however, you can still distinguish its noise against the background of other system components. These are the consequences of using 65nm manufacturing technology.
To be fair we have to say that despite poor acoustic performance, the cooling on both cards is superb. You can certainly sacrifice that for the sake of quieter operation by lowering the rotation speed of the cooler fan using corresponding software. Just make sure the GPU temperature never exceeds 105ºC, because at this point the automatic overheating protection kicks in and reduces the frequencies and hence slows down the cards.
The new cards no longer suffer from any compatibility issues that used to be common for G80 and G92: both cards from Nvidia GeForce GTX 200 family booted and worked perfectly fine on our test boards without PCI Express 2.0, as well as on an Intel X38 based board supporting this protocol.