Can a bad but sufficient PSU affect performance?

[Deleted]

Can a bad but sufficient PSU affect performance?

I have a 550watt PSU on which I hooked an SSD, a HDD, i5 3470 and my AMD 7950.
It all works, but I've often wondered, since this should be near the load capacity, does it negatively impact my performance?

I can run WoW all settings full in calm areas no problem, but when I gaze into the distance, especially in Pandaland, Even with graphic settings which I am content and not nearly heavy loading in comparison to maxed, I still drop to 55fps, which bugs me like mad.

[Deleted]

Your system at ~90% will probably not pull more than like 300W max. 550W PSU is more than fine. 55fps sounds perfectly fine, ~5fps from max is hardly noticeable.

[Deleted]

It shouldn't affect performance. If your PSU struggles most often it results in blue screens, freezes or other "weird" behavior while under heavy load. But your CPU or GPU won't clock down because they don't get enough voltage.

[Deleted]

Your system at ~90% will probably not pull more than like 300W max. 550W PSU is more than fine. 55fps sounds perfectly fine, ~5fps from max is hardly noticeable.

Thanks, but those 5fps rub me the wrong way... It's so damn noticeable if you're used to 60fps, I can understand it happens when raiding, but going in a dungeon getting 60fps then teleporting out to 55fps irks me. :P

---------- Post added 2013-06-19 at 12:57 PM ----------

It shouldn't affect performance. If your PSU struggles most often it results in blue screens, freezes or other "weird" behavior while under heavy load. But your CPU or GPU won't clock down because they don't get enough voltage.

Thanks, I have nothing to worry about then.

[vesseblah]

Can a bad but sufficient PSU affect performance?

No, bad or insufficient PSU will only affect system stability, never performance.

[Deleted]

why do you think it's the PSU that's causing you to "lose" 5 fps?

[Tankendog]

Use Vertical Sync. Doesn't matter how high your FPS will go then, as it will be synced with your refresh rate, providing smoother gameplay visually. This is more noticeable the larger the screen. FPS isnt everthing. A image needs to be fluid. It is much more noticeable when it is not, causing portions of the screen to refresh at different rates. Your goal should be to aim for a fluid experience, not max frame rate.

[Cyanotical]

No, bad or insufficient PSU will only affect system stability, never performance.

it can cause issues in multi card setups, on mine there is a night and day difference in smoothness between when i have the auxiliary 6pin connector plugged in and when i don't, and it also affects benchmark scores, but thats not exactly standard on most motherboards

[Deleted]

Use Vertical Sync. Doesn't matter how high your FPS will go then, as it will be synced with your refresh rate, providing smoother gameplay visually. This is more noticeable the larger the screen. FPS isnt everthing. A image needs to be fluid. It is much more noticeable when it is not, causing portions of the screen to refresh at different rates. Your goal should be to aim for a fluid experience, not max frame rate.

I am, without it I easily reach 250fps on calm area's, it's just that Pandaria area's when I'm outside drop me slightly below.

[Deleted]

it can cause issues in multi card setups, on mine there is a night and day difference in smoothness between when i have the auxiliary 6pin connector plugged in and when i don't, and it also affects benchmark scores, but thats not exactly standard on most motherboards

Why would you even use the 6 pin? weren't the need for those ports requiring the extra power replaced by PCI?

[Cyanotical]

Why would you even use the 6 pin? weren't the need for those ports requiring the extra power replaced by PCI?

the 6 pin is auxiliary power for the PCI lanes

[Deleted]

the 6 pin is auxiliary power for the PCI lanes

right.. didn't even think of that /facepalm

[vesseblah]

the 6 pin is auxiliary power for the PCI lanes

Hmm... TTL said recently he's never needed those, even when doing stuff like benchmarking quad-CF with 7970's.

[Cyanotical]

Hmm... TTL said recently he's never needed those, even when doing stuff like benchmarking quad-CF with 7970's.

yeah, i remember that video, so i unplugged it when i switched to the FT02, and then couldn't figure out where i gained all this stuttering and minor drop in performance, i thought i had seated one of my cards wrong, i spent a few hours troubleshooting it, and finally plugged the 6 pin back in and instantly my stuttering was gone again

so, TTL was wrong on that, and good clean power can make a performance difference, but thats at the top end, i highly doubt its going to do anything on a standard single gpu setup

[vesseblah]

Or you have crappier mobo. Or it's different with quad SLI/older cards. Or he got lucky.

Anyway, I'd call that stability problem if some of your cards dont work, not actual performance loss in the way OP asked.

[Cyanotical]

Or you have crappier mobo. Or it's different with quad SLI/older cards. Or he got lucky.

Anyway, I'd call that stability problem if some of your cards dont work, not actual performance loss in the way OP asked.

i also had similar problems with 590s and single braided extensions, different board, different cards, but similar issue, unclean power does affect performance

also, iirc, TTL was also using a R4E for the 7970 quadfire test, there isn't a better board for x79 atm

[Faithh]

the 6 pin is auxiliary power for the PCI lanes

According to linus, the extra 6pin is to prevent the 24pin being burned out. He says it somewhere in this video It's mostly recommended to use it for Quad sli setups.