[newman]

Actually I accidentally put in some wrong info into the calc. Recalculating shows max required wattage at some 560. So I think I'll just leave it for now. The PSU doesn't even get very hot during operation.

[Iss Mneur]

And I've never really had much success with air cans myself...as soon as they start getting cold, the airflow drops off dramatically

Well, since its butane after all

Yep.  Short bursts rather than long blasts.  Preferably with two cans that you can switch back and forth with fairly quickly (if you only have one machine, get the two pack of the smaller cans, rather than one big one they will last longer).


Regarding the power supply wattage, the reason there is so much debate, is that some (generally cheaper) manufacturers don't design their power supplies to run at maximum load, so you get the power supply up near max load and the voltages start to wander.

The other thing to consider with PC power supplies is that they provide 12V, 5V, 3.3V and sometimes -5V, plus 5V standby as long as it has AC power.  Which also results in problems if the power supply design is not perfect where the load on the primary 3 voltages is not even resulting in the voltage of the one or two that is heavily loaded dropping out of range or the other one or two climbing out of range.

The other problem is the power demands of a PC have shifted over the decade, from the removal of the -5V from CPUs, to the rise of the Aux power 12V power for the CPUs (P4), to the rise of the GPUs that run on primarily 12V and draw as much as the CPU itself.  This results in the the balance of output power of the PC power supply shifting a large amount, invalidating good design and general practice along the way.

The other thing to keep in mind the number on the box of a PC power supply is generally the sum of the wattages for voltages and all rails, which is a pretty useless metric.  This means that these kilowatt power supplies get most of that number from the amount of power that the 12V rail(s) provide, something like 50A, (600W) which is normally only useful when you are talking about multiple GPUs.  This means the best way to determine if your power supply is cut out for the job is to check what each component draws from each voltage class and base your purchasing decision there.

Regarding the closeness to the max I would suggest shooting for 80% of power supply load, which is typically the peak of the efficiency graph, but of course this always depends on the power supply itself and how you use the PC (mostly at full load? mostly at idle?).  Also, (personal view) don't buy the crap power supplies that can't manage to get an 80% (Bronze) efficiency (average) rating.

[newman]

Also, (personal view) don't buy the crap power supplies that can't manage to get an 80% (Bronze) efficiency (average) rating.

I completely agree which is why I'm running a Corsair. Sure the TX series is usually withing bronze/sometimes silver efficiency rating and not gold, but they're still very solid.

[Mikes]

Also, (personal view) don't buy the crap power supplies that can't manage to get an 80% (Bronze) efficiency (average) rating.

I completely agree which is why I'm running a Corsair. Sure the TX series is usually withing bronze/sometimes silver efficiency rating and not gold, but they're still very solid.

Does Corsair still have the lose screw issues mention on johnnyguru with pretty much all their tested units? Always kept me from buying one.

[newman]

Does Corsair still have the lose screw issues mention on johnnyguru with pretty much all their tested units? Always kept me from buying one.

Never had any issues at all.

[CP5670]

I haven't seen any such problem on mine either.

The other thing to keep in mind the number on the box of a PC power supply is generally the sum of the wattages for voltages and all rails, which is a pretty useless metric.  This means that these kilowatt power supplies get most of that number from the amount of power that the 12V rail(s) provide, something like 50A, (600W) which is normally only useful when you are talking about multiple GPUs.  This means the best way to determine if your power supply is cut out for the job is to check what each component draws from each voltage class and base your purchasing decision there.

It's true that the overall wattage number is irrelevant, but the 12V capacity and regulation is the main thing that matters these days. The vast majority of a modern PC's power draw comes from that line.

[newman]

Update: my PSU died today. Looks like JGZinv was absolutely correct. I replaced it with a Corsair AX 850W PSU, fortunately the old PSU didn't fry any other components when it died. Either both JGZinv and me had really bad luck or the Corsair 650W TX series isn't all that great, as it really should have been able to run my system fine.

[Astronomiya]

I just did some quick Googling, and found that unlike most Corsair PSUs, the TX's weren't made by Seasonic.  This was reflected in their not awesome performance.  The AX series are Seasonic designs, so I would be very surprised if you had any more problems, though I still think you got a PSU that's a mite too large.

[newman]

though I still think you got a PSU that's a mite too large.

Perhaps, but this is a gold rated PSU so the efficiency should remain on very high percentages (around 90%) at all times. This way at least I don't have to worry when putting in new hardware - I know the PSU can handle it.

edit:
I'd also like to point out that the Corsair AX 850 PSU is damn near silent. It'll only ever even use the fan if the load is over 50%..  In my book that alone makes it worth the (admittedly) hefty price.