Speed Problem with R9 295X2

[epixoip]

No. Again, power supply is irrelevant. The card will do everything it can to keep power consumption under 500W, and that means throttling the GPUs.

[devilsadvocate]

But a 1600 W PSU like "Super Flower Leadex 80 Plus Titanium" should handle 2 of these cards and a cpu rite? I gona put it under water so temps wont be a issue.

There are builds with 2 295x2's, but they are power hungry monsters. They usually pull close to 1400 watts from the wall. Considering that most electrical sockets (at least in the United States) are only 15 AMP circuits, then that means that the maximum load on a 15 AMP circuit is only 1800 watts or close to that.

The only thing I would tell you is that if you want to build a system like that, then you might want to move it to your living room, where the 20 AMP circuits are usually located due to entertainment center power requirements. To put a system with 2 295x2's (and who knows what else) on one circuit is asking for problems with either power stability or circuit overload. The risks are very real. Worst case scenario is either a blown breaker or an electrical fire (or both).

The build can be done (I have seen a few), but be aware of the power requirements.

Have fun!

[Rolf]

Necromancy makes you feel good, eh?

[devilsadvocate]

Necromancy makes you feel good, eh?

I thought I would contribute something. Some people (myself included) still run 295x2's. Mine was nothing but problems for months and information was scarce a year ago, when I got the card. I actually had to RMA my first one and had to get another (I digress).

Most people haven't considered the associated power supply settings with the 295x2. This was certainly an oversight of mine when I started out with this card. When simply load testing and benchmarking (nevermind oclHashcat benchmarking) my 295x2, it would crash my entire system. GPU-Z and 3DMark would crash Windows 8 and reboot the system. This would eventually lead to me RMAing the card, but I did find this guide on OCP settings in the process.

http://www.corsair.com/en-us/blog/2014/m...he-ax1500i

When adjusting the Over Current Protection settings, I followed one of the recommendations at that link. I deactivated it with the Corsair link software.

"The other method that can be used is to turn off the OCP altogether. To do this, you must check all of the boxes for OCP and then uncheck them. After no more than 15 seconds, OCP will be disabled on the AX1500i power supply."

I had to do that with the Windows software and hope that the settings were persistent across reboots. They seemed to be.

After running od6config with autofix (or manual settings), I haven't had any noticeable issues when running oclHashcat. The factory water cooling of the 295x2 along with running a couple fans next to the GPU keep the temperatures in check and avoid Powertune thresholds that trigger throttling.

All of that being said, the 295x2 is really a bad option if you are serious about GPU horsepower, but who am I telling? I won't be getting another one. There are so many other better options out now. Nvidia looks like it will be the way of the future in this regard.

Necromancy for the win. Until next time.