PCI-E 2.0 Standard and Geforce GCs

Szark

good info MJC cheers. 

JCThomas

hphoenix said:

JCThomas said:

Glad to see you're getting lots of helpful information.

However, 280-300 Watts is an extreme overestimate of your system's current power consumption. Not meaning to be a contrarion, but the 400W requirement listed on Nvidia's site is actually meant to be conservative, as are all of their guidelines. They're there in case you have a very poor quality PSU. Anything 80+ that's not some off-brand would be fine. If all you're going to add is the 960, anything over 500W would be extreme overkill.

Always good to have room to grow, but if you're planning on sticking with the 960, no reason to spend the extra money on more watts. For some perspective, I recently built a gaming box, mostly just for the fun of the build, with an i5-4590, 128GB SSD, 2TB HDD, 8GB RAM, and a GTX 970 on a small-form factor 450W Silverstone PSU. It is more than enough.

Your 3770 has a TDP of 77W. While TDP isn't an exact measure of how much power your CPU will consume, it's still pretty close. Even doubling TDP to estimate consumption, say 150W, would be very far on the safe side. Your system now is probably consuming somewhere around 100W at load.

Even this would do, and only 20 USD after rebate:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139026

Sorry, this is incorrect.  TDP is Thermal Dissipated Power.  Not all power is dissipated thermally (though most is) and the CPU may have a TDP of 77W at AVERAGE, the peak consumed power can spike much higher under full load.  Don't believe me?  Hook up a watt-meter to the PS, and watch the difference between idle and full bore on all cores.  And 77W is a conservative measure of IDLE power consumption.  Load power is measured for the 3770k at 166W.  (see http://www.bit-tech.net/hardware/2012/04/23/intel-core-i7-3770k-review/8 )

Furthermore, you don't want the PS to be running at full rating even at full load, as power supply efficiency and regulation drop dramatically once you are at 80% of rating.  Look at some good tech reviews, you'll find the graphs of regulation vs. load and efficiency vs. load all over the place.

I've been building systems for almost 30 years.  I've also been an Electrical Engineer for about 20.  Trust me, for this system, you'll want the 750W.  Go below that and when you have it going full-blast on a heavy render, and something chugs the CPU and drives to full load......you'll get drop-outs, or even shutdowns/bluescreens.  Seen it happen ALL the time.

AVERAGE users don't ever peg all their cores at once and max out the GPU.  So they don't require the kind of power that people doing rendering do.  Browsing the web, even most gaming, won't peg all the cores and the GPU simultaneously.  Heck, it's tough to do with a lot of rendering software.....but it does happen.  And when it does, having the system stay up and running, rather than blue-screen or shutdown, makes a big difference.

Thanks for correcting me. I'd also missed that this was meant for two 960s. Great info on TDP and thanks for the link.