Arghh help, power supply problem?

[tygk]

Basically I'm using a OCZ 600W ModXStream Pro power supply, along with a gigabyte 560 ti oc. I was having lots of freezing problems especially within games and as soon as I took the graphics card out the freezing stopped. This now means that it is either my graphics card with issues or my power supply. My 560 ti requires 31 amps on the 12v rail. My power supply has 2 12v rails outputting 25 amps each. Do I have enough power, is it probably just my graphics card causing problems or should I be concerned about my power supply also? I have returned my old graphics card and am awaiting my new pny 560 ti oc2 which should arrive tomorrow. Please someone help

 

[jonnyrb]

If it was the PSU, it would probably run okay, but the PSU would die eventually. Just be sure to hook the card up on separate rails

 

[clarkjd]

It's possible that the freezing is heat related. Check the temps of your GPU just prior to the freezes.

 

[ram1009]

Why would you doubt what your GPU OEM says? If it says 31AMPS and you only give it 25 it has a 20% deficit. This is the problem with multiple voltage rails. Even though your PSU can supply enough current to run your GPU you can't get it to the board because it's split between rails.

 

[clarkjd]

Why would you doubt what your GPU OEM says? If it says 31AMPS and you only give it 25 it has a 20% deficit. This is the problem with multiple voltage rails. Even though your PSU can supply enough current to run your GPU you can't get it to the board because it's split between rails.

While you are correct in theory, the Graphics card has 2 6-pin power connectors, and therefore requires two power connections. If he has both connected, then the limites of the individual rails on the PSU would not come into play. Most dual -rail PSUs are really single rails when you get to their actuall construction.

Bottom line -- He should be able to run that video card with that PSU without a problem.

 

[RetiredChief]

Quote: Our test system is based on a power hungry Core i7 965 / X58 system. This setup is overclocked to 3.75 GHz.
System Wattage with GPU in FULL Stress = 319W End quote:

Problem - PSU, Temps, Drivers:
.. (A) ForGet this multirail/single rail - NOT Applicable. This card is NOT drawing more than 20 Amps from a given rail. The 31 Amps is a recommendation and is for Total Current from all rails and is for complete system - That 31 amps is divide among the 12 Volt: 4/8 pin ATA connector, The 20/24 Pin connector, the 6/8 pin PCI-e connector(s), and the Molex power connectors going to HDDs and CD/DVD drives. A 600 Watt PSU is plenty. That said, it could still be a power problem. Use a program to Monitor voltage (Primarilly the +12V rail). I use CPUID HWMonitor - Does not work on all MBs so look at idle should be +11.4 -> 12.6V and if it is an off the wall reading program is at fault, try another program - ie utility disk for MB. Now Download and run Furmark (in a window so you can see voltages). If with furmark running the voltage drops below 11.6 V - Ditch the PSU (Spec is 11.4V). Just for info: the Max current per pair of pins is around 5 Amps which is based on the IsqR drop accross the male/female pins. Normal design is less. The only real dif between a single rail and a mutirail PSU is that you do not have to be concerned about amount of current drawn on a single rail. With a single rail psu, if you are drawing more than what a "good" multirail PSU does off of a say 6 pin pci-e connection - you have a problem. The GPU Manuf has NO control of which type PSU you use and will NOT design a GPU that pulls more than 20 Amps from a single rail. NOTE a single 20 Amp rail can supply upto 240 Watts

..(B) Temperatures, CPU and GPU. Open a temp program tha will display both CPU and GPU (Again I use HWMonitor). Run furmark, in window, Monitor GPU temp. For CPU I use Prime 95 (Will heat CPU more than any game). Only need to run for 15 Min - Monitor Temps closely. For stabilty check run for 4 -> 8 Hours, but again monitorcpu (core temps) closely for first 15 Minutes. If they look ok then go watch TV/Play with Spouse, or whatever, but check temps once every 15 Min.

..(C) A driver problem. Uninstall GPU driver, run a registry cleaner (I use CCleaner). re-install gpu driver.

 

[tygk]

I have reinstalled the drivers with no luck, the temperatures are all very normal, I not longer have the graphics card and cannot test the voltage, I will do so tomorrow when my new graphics card arrives

 

[tygk]

but sorry just to clarify I should have enough power across the 12v rail?

 

[RetiredChief]

Yes, a Good 450 Watt PSU will handle your system, But would recommend a Min of 500 Watt PSU - Just make sure it is a quality PSU. Just pick one and before buying google reviews for it.

 

[tygk]

Yeah the reviews are looking good for the one I got, I might just have a funny power supply, I'll find out when my new graphics card comes today