the importance of a good PSU

[MichaelZ]

This is more of an OCing question than general hardware. how much difference would a good PSU make to overclocking? I do believe Jeff or shady06 asked about this before, but I don't think they got many hits. Just thought I'd ask again for the hell of it.

I'm not talking the power rating, more about the rail stability and such. For example. My friend recently got a nice Enermax 450W after selling his Antec 550W True Control. He claims previously he was unable to OC his 2.8C past 3.5Ghz def voltage (this I can confirm). Now he's claiming hitting 3.75Ghz on stock voltage. Case left open + SP90 with a 80mm fan. Which to me seems kind of far fetched for a D1 stepping 2.8C & ASUS P4C800 paired up to a set of very respectable pair of 256MB Corsair XMS PC3500 BH5 chips running 2,2,2,5 and overclocked and running 1:1. It's not prime tested at this speed but he claimes it runs 3dmark for 2 hours looped and that's good enough for him.

I'm currently running a 500W not so well known PSU but it gets the job done with my 2HD, 2 optical drives, many case fans + lighting installed and an OCed P4 3.0C. However I'm just wondering if a good stable power rail for Intel would help a chip OC more. (the chip being the bigger limiting factor obviously but still, curious to know).

Currently I'm running a 3.0C @ 3.55Ghz stock voltage ~ 1.472V Cooled by Zalman 7000A-Cu (tested and fully stable for 24/7 use). I can get to 3.7Ghz ~ 1.55V but unfortunatly it's not stable for everyday use. Prime proved this after only 30 mins and running 3.66ghz on 1.55V lasted a good while longer, but still not rock solid like I want. Crashed after 2 hours of 100% CPU load.

Just wanted to know if an Enermax PSU can really make such a difference for a Intel rig. My PSU fan recently started making noises and since you can't really replace the fan unless you solder, I'm slightly interested in a new PSU. Antec is good, but for Intel, Enermax is the way to go it seems. After hearing this little piece of believe it or not, it got me thinking.

Anyone got some comments?

 

[myocardia]

Okay, man, here's the way the whole psu cookie crumbles. Since most people don't come here complaing unless their computer crashes or reboots when they do certain things, that's mostly what you'll read about around here. But that doesn't mean that quite a few of the people who come to this forum don't need a more powerful psu. Most of them think that because their chip will only do __mhz, that's all their chip will do. Now, this can very well be true, but it's definitely not always true. You need not only a large amount of current available, but you need that current to be as stable as possible. This is the reason why almost all of us who use Antec psu's use the TruePower series; they have dedicated rails, unlike most psu's where the 3v rail and the 5v rail are combined. That's why on the cheaper psu's, you'll see them give two different amperages for the 3.3v and the 5v rail. The larger one is how much 3.3v that psu can put out with absolutely no 5v or even 12v output. The TruePower's can put out what they say they can into all three rails simultaneously. The Enermax's are the same, they have discreet rails. Now, Antec's are awesome for Athlons, because they have prodigious amounts of 5v amperage, which is what the Athlons require when being overclocked. But, they aren't very good at all for P4's because they don't have enough 12v amperage, like the Enermax's do. This 460 watt Enermax: link has over 10 amps more 12v juice than my Antec TruePower 480 has. Now, I find it hard to believe that your friend has any stepping of 2.8C that's running 3.75ghz on stock voltage. It may be possible, but I haven't heard of any P4C that will overclock a gigahertz on stock voltage. If his chip will do that, try to talk him out of it. Oh, and yes, you would have a more stable system, if you got that 460 watt Enermax I linked to. There are people running 3.0C's and 3.2C's at 4.0ghz with that same psu.

 

[Verdant]

yes its important for overclockers, and computers that need extreme stability...

on the flip side however, for the average user (read: machines you make your neighbour and your mother)
you can probably skimp a little... by skimp i don't mean generic, i mean buy the cheaper brandname ones, like the entry level antecs
which i have used in some rigs that are overclocked with voltages and worked fine (but i don't fully trust it)

 

[myocardia]

Sure, for instance, a $45 Antec SL350 would be just fine, even for overclocking an XP2500 to 11x200, even with 2 or 3 hd's and 2 optical drives. It's just not what you want for extreme overclocking, like what I do. But, more people are also wanting higher-end video cards in their computers these days, it seems (I mean people who couldn't even add a stick of ram to their own computer, not people like us). Did you know that a 9800XT can use 200 watts of power? Even a 5700 Pro can use up to 150 watts. That's alot of power! I'll look for the link to that review that has power consumption for all of the video cards.

 

[Verdant]

Originally posted by: myocardia
Sure, for instance, a $45 Antec SL350 would be just fine, even for overclocking an XP2500 to 11x200, even with 2 or 3 hd's and 2 optical drives. It's just not what you want for extreme overclocking, like what I do. But, more people are also wanting higher-end video cards in their computers these days, it seems (I mean people who couldn't even add a stick of ram to their own computer, not people like us). Did you know that a 9800XT can use 200 watts of power? Even a 5700 Pro can use up to 150 watts. That's alot of power! I'll look for the link to that review that has power consumption for all of the video cards.

thats more than i thought, but not more than i would have estimated if i actually though about it

still the remainder of the usage is going to be low...

any idea how much the slower cards consume?

if i am building a multimonitor system that requires 2 video cards (1 highend and one pci say... a radeon 7000 or equiv) this would be nice to know

 

[myocardia]

I don't personally, this particular review/comparison only had 4 or 5 of the most used cards today. But, even if you have a 9800 Pro, as long as you aren't playing the most videocard-demanding game on the market today, it's not going to use that kind of power either. I would probably guess ~40 watts max. for a pci Radeon 7000.

 

[MichaelZ]

Originally posted by: myocardiaI find it hard to believe that your friend has any stepping of 2.8C that's running 3.75ghz on stock voltage. It may be possible, but I haven't heard of any P4C that will overclock a gigahertz on stock voltage. If his chip will do that, try to talk him out of it. Oh, and yes, you would have a more stable system, if you got that 460 watt Enermax I linked to. There are people running 3.0C's and 3.2C's at 4.0ghz with that same psu.

Man, I haven't confirmed that thing running @ 3.7 ~ 3.75 (case opened) but I do know for a fact he can run 3.5Ghz def voltage stable. I'm going over there sometime this weekend, will try and confirm if he's telling the truth or not... as for convincing him out of it, he would probably rather kill himself than give up that CPU.

I might grab a new PSU later after I get an NV40. I always thought a good stable PSU would result in a better overclock but let's face it, a huge leap in graphics performance should always come before getting more Mhz

Another thing... I can't seem to find a local supplier (Australian) of Enermax PSUs. Most places have mostly no name crap. Only respectable brands are Antec, Zalman, Thermaltake PSU's. I'll have to look around through suppliers that have Enermax. Does Newegg ship overseas? If they do I'll grab some AS5 as well cause they're 20 bucks a pop here. If all that falls through would an Antec 550 TC still be a good step forward for overclocking my rig?

 

[Outrider]

Originally posted by: myocardia
Did you know that a 9800XT can use 200 watts of power? Even a 5700 Pro can use up to 150 watts. That's alot of power! I'll look for the link to that review that has power consumption for all of the video cards.

Matey, I hate to say this but that is a whole load of bull. Even the worst and infamous guzzler from nVidia, the dustbuster 5800 Ultra don't chew off no more than 80W at most doing the most demanding games. Look at the AGP specs, think about how much needs to be done to dissipate 150 to 200W of power and you'll know it's ridiculous.

Whoever told you or wrote that information on a web, you should ask him what's he smoking, gotta be something really powerful.

 

[Hendrietta]

myocardia was kinda right. the watts he specified was correct but if i remember right the article said it only needed that much upon power on. lemme look for the link.

wow only took me 3 secs to find it . http://www20.tomshardware.com/graphic/20040405/gddr3-11.html

the watts u see in the link seems to be measured from the overall system, not the card alone.

 

[Zebo]

Enermaxs are the real "true power" with a massive 36 amps accross the board on their 465's MODLES. If it wer'nt so loud I'd not RMA it back to newegg. Antec True 480 I had blew. And Coolermax "550" (lie) crashed the system when running prime and 3dmock2003 together. Important.

 

[MichaelZ]

well i've confirmed that his system isn't stable @ 3.75, supprise supprise

did a few burn in apps and crashed pretty quickly. he did however squeeze a extra 100mhz out of that 2.8C though. 3.6ghz is running stable on def voltage. not bad...

as for the PSU. i'll probably try and find a local enermax supplier but after i get me a NV40.

 

[MichaelZ]

well i've confirmed that his system isn't stable @ 3.75, supprise supprise

did a few burn in apps and crashed pretty quickly. he did however squeeze a extra 100mhz out of that 2.8C though. 3.6ghz is running stable on def voltage. not bad...

as for the PSU. i'll probably try and find a local enermax supplier but after i get me a NV40.

 

[BlindBartimaeus]

Bah to the double postage!

I would like to say I have had an Enermax 465, Sunflower 520, and I now have 2 Enlight 420's. Yes I droped down in wattage rating BUT I actually got the idea screwin around with a 360 from enlight. I was puttin a cheap system together for a friend but was going to overclock it quite a bit. I figured I will just leave this supply in till I am done and swap it out. 2.25 gig on a XP machine, and EVERY rail was right on...I said...hmmm... These PSU's are EXTREMELY quiet and very strong...much stronger than their ratings suggest. Most importantly they are quiet. I picked up my second one that I don't even have a use for, but it was a refurb at newegg for 22 bucks shipped...had to liberate it.

I highly recommend this powersupply for ANY system that doesn't require liquid nitrogen or a prommy.

 

[Outrider]

Originally posted by: Hendrietta
myocardia was kinda right. the watts he specified was correct but if i remember right the article said it only needed that much upon power on. lemme look for the link.

wow only took me 3 secs to find it . http://www20.tomshardware.com/graphic/20040405/gddr3-11.html

the watts u see in the link seems to be measured from the overall system, not the card alone.

While he's got the numbers correct, myocardia should had been more careful reading what the numbers really are as opposed to what the article claims... since it came from THG

Based on the device they are using, it's definitely the entire system. On top of that, it probably reports the wattage the PSU is drawing, including the waste from conversion inefficiency.

From my own past experiments, the much higher startup currents is likely due to the fact while booting, the CPU don't get the halt instructions.

THG has long since been a joke in my books so I was also right in telling myocardia to ask what they've been smoking...