X-bit labs

Affordable Multi-GPU: Two GeForce 9600 GT in SLI (page 4)

Category: Video

by Alexey Stepin

[ 04/19/2008 | 01:41 PM ]

Power Consumption, Noise, Temperature, Overclockability, Compatibility

As opposed to the Gainward Bliss 9600 GT 512MB GS we reviewed earlier, the Gigabyte GV-NX96T512H-B is a copy of the reference card. So, we measured its power consumption again using the following testbed:

• AMD Athlon 64 FX-55 CPU (2.6GHz)
• EPoX EP9-NPA+ SLI mainboard (Nvidia nForce4 SLI)
• PC3200 DDR SDRAM (2x512MB, 200MHz)
• Western Digital Raptor WD360ADFD hard disk drive (36GB, SATA-150, 16MB buffer)
• Chieftec ATX-400-212 power supply (410W)
• Microsoft Windows Vista Ultimate 32-bit
• Futuremark PCMark05 Build 1.2.0
• Futuremark 3DMark06 Build 1.1.0

The card is loaded in 3D mode by the first SM3.0/HDR test from 3DMark06 launched in a loop at 1600x1200 with 4x FSAA and 16x AF. In the Peak 2D mode the card performed the 2D Transparent Windows test from PCMark05. Here are the results:

Despite the considerable discrepancies in the power circuit design, the cards from Gigabyte and Gainward have almost identical results. The biggest load is on the external power connector, yet it is not higher than 32W. The total power draw is not higher than 60-61W. That’s an excellent result for the performance the GeForce 9600 GT delivers in games.

Comparing the theoretical peak power draw of two SLI-linked GeForce 9600 GT cards, which is about 120W, they consume somewhat more than the GeForce 9800 GTX and GeForce 8800 GTS 512MB (about 100W) but less than cards like ATI Radeon HD 3870 X2 or Nvidia GeForce 9800 GX2 (consuming 170W and 180W, respectively).

We measured the level of noise produced by the card with a digital sound-level meter Velleman DVM1326 using A-curve weighing. The level of ambient noise in our lab was 36dBA and the level of noise at a distance of 1 meter from the working testbed with a passively cooled graphics card inside was 43dBA.

The reference single-slot cooler proved to be no louder than the advanced dual-slot system from Gainward. Its efficiency is lower, though. The GPU temperature is 45-46°C when idle and grows to 62°C under load. For comparison, the Gainward Bliss 9600 GT 512MB GS has a GPU temperature of 42°C and 58°C when idle and under load although the card is pre-overclocked. The difference is not big, however. And 62°C is not really high for a modern GPU – we are accustomed to much higher numbers. The G94 is indeed a very lucky chip in terms of electrical and thermal characteristics.

The GeForce 9600 GT doesn’t change the fan speed when switching from 3D to 2D mode, so two such cards are going to produce more noise than such quiet cards as GeForce 8800 GTS, 9800 GTX and Radeon HD 3870 X2.

Our overclocking attempt proved to be a success despite the compact cooler. The highest GPU frequency the card was stable at was 770/1925MHz. That’s far better than we achieved with the Gainward card. The memory could overclock to 1100 (2200) MHz. That’s quite a good result for non-extreme overclocking.

We didn’t have any compatibility problems with the Gigabyte GV-NX96T512H-B card. It started up successfully on every PCI Express 1.0a and 1.1 mainboard we tried it with and passed the tests normally.