Zotac 9300 ITX WiFi + BFG 9800GT Eco = Wifi fiasco

betaspin · 11 Aug 2009 at 09:56

After an evening wasted on trying to make a BFG GeForce 9800GT EcoIntelligence 512MB work properly with a Zotac 9300 ITX WiFi MB inside a Sugo SG05, I am close to giving up and returning the card.

There are two major problems, the first of which is that the performance of the wireless module on the 9300 ITX drops like a stone with the BFG 9800GT installed. Without the BFG 9800GT, the wireless connection to the router is always b/n 48-54 Mbps, but with the graphics card it goes down to 2-5Mbps. I guess that there is some EMI associated with the BFG 9800GT, which could come from the pwm fan, or from poor pcb design. I would much appreciate it if other members, who are using the same MB with a discrete graphics card, could let me know if they have experienced wireless performance deterioration after the installation of the graphics card.

The second unpleasant observation is that the pwm fan on the BFG 9800GT quickly goes up to maximum rpm with increased load, but then continues to stay at maximum speed forever, even when the GPU temperature has dropped down to 40C. I can probably live with this, adjusting the fan speed with RivaTuner as required, if I could find a solution to the wireless problem.

The addition of the BFG 9800GT and the associated decrease of the air circulation inside the SG05 has made the MCP idle temperature go from 54C to 62C (at ambient temperature 25C).

betaspin · 11 Aug 2009 at 13:21

Thanks, this was one of the first thoughts that crossed my mind, but the power should be all right. The psu is the standard SG05 300W, and the system with the 9800GT EcoIntelligence maxed in FurMark measures just under 150W at the plug. The power requirements of the usb wireless module are next to negligible, one of the 9300 ITX reviews estimated it at about 5W.

betaspin · 11 Aug 2009 at 14:16

I think that Geckovich is running a system with a discrete card, ITX PC: E8500 @ stock, 4gb, 320gb, 4870, 9300-ITX. If he had any wireless problems, he would have complained, as there was a recent wireless thread, http://forums.overclockers.co.uk/showthread.php?t=18040657, to which he contributed.

betaspin · 11 Aug 2009 at 16:29

Thanks, I was thinking about a HomePlug pair, as this is the only type of "cabling" that I would be able to tolerate, but then I brought my laptop close to the offending card and guess what, its wireless connection rate went down from 54Mbps to 24Mbps! The BFG card is definitely going back, as I am quite sure that it must be faulty to generate that much EMI.

I am reluctant to try with another BFG Eco card as, apart from the problems, the cooling system is pushing too much hot air towards the front of the SG05. The other 9800GT Eco card that is around is the ZOTAC GeForce 9800 GT Eco. Has anyone seen it in action?

betaspin · 11 Aug 2009 at 19:49

If the case is moved closer to the router, the speed increases a bit, but not to the extent to which it increases when the BFG card is not inside.

Weird problem---people have been having problems with interference b/n graphics cards and sound cards, but I have not been able to find almost anything about gpu-caused interference affecting wireless. It is definitely not a driver issue, as the onboard gpu is using exactly the same NVidia driver.

betaspin · 28 Aug 2009 at 20:59

Yes, I did. I returned the BFG GeForce 9800GT EcoIntelligence 512MB and got an EVGA GTS 250 512MB instead. The internal wireless card was working significantly better with the EVGA, but still a bit worse than in the absence of a graphics card. My next move was to get an Edimax EW-7711UAN USB wireless adapter (just about £12), and this solved all wireless problems.

I still think that the BFG was producing way too much EMI, but another fact is that the stock internal wireless card is quite poor, even if used with a 5dbi antenna (the one that comes with the card is 3dbi).