Power Supply Advice

[camalbitboy]

Hi All,

I've just discovered that my 600W Tagan PSU can't cope with my system. I kept getting crashes on some games and having tried running with just 1 graphics card it works fine. I tested with each 460 card to make sure that it wasn't a card specific issue, and put my 2 8800 GT's backin to make sure there wasn't an SLI issue with the board. So I'm pretty sure its a PSU issue. This could also be why I never got a particularly great stable OC on this kit as well. (spec in my details)

So I'm thinking a more powerful PSU and have come up with either coolermaster silent pro gold 1000w or Corsair HX850W modular. The coolermaster is 1kw and £15 more expensivem, but the Corsair seems to get better reviews. Will I need the extra 150W? (thinking of futureproofing here) and is the extra £15 worth it?

The other bonus is the Corsair unit has more connectors available, inc 6 4+2 pin connectors.

Thoughts please.

Cam

[Sputnik]

A good 700watt or more should do it. You should have a read on some recent threads to do with PSU's before buying.

[GoNz0]

enermax

[camalbitboy]

Oh and any other advice on quick checks to help me be sure its the pay would be appreciated.

[planet436]

The Corsair definitely over those two. The Coolermaster isn't reviewed over at Jonnyguru (the 1200 one is but has problem with ripple and noise). The 850HX is a popular model, very good efficiency and ripple control and doesn't suffer from lowering QC that the lower end models are suspected of having.

850w is probably slightly overkill even with two GFX though.

[Sputnik]

enermax

At least you know who they are made by without having to do any research

[GoNz0]

you also know that they rating is the constant one such as my 1250W that will run at 1500W but may go above its happy to run 24/7 @ 50 degrees C if you push it past 1250w...

[camalbitboy]

enermax

Well that was good advice just for their psu calculator! Need 850 for my rig according to it, 975 if I want to oc. So looking at the 1k corsair plus enermax ones when I find some.

[Sputnik]

Well that was good advice just for their psu calculator! Need 850 for my rig according to it, 975 if I want to oc. So looking at the 1k corsair plus enermax ones when I find some.

I tried your spec with the PSU calc. and with 10% capacitor ageing and overclocking to 3000Mhz I still only got a figure of 697watts.

[camalbitboy]

I tried your spec with the PSU calc. and with 10% capacitor ageing and overclocking to 3000Mhz I still only got a figure of 697watts.

Hmm your right, I managed to select quad socket by mistake (using android phone so tricky to use that site). I get a non oc of 574w and on an oc of 3gig and a little extra vcore 620w.

So that then begs the question as to why my 600W tagan with no oc on the cpu is not running 2 460's successfully. Hmm i'd better to do some further investigation to check it def is the psu before splashing out on a new one.

Thanx for spotting my mistake.

[planet436]

Psu's generally degrade by 10% per year and lowish quality psus like Tagans are unlikely to be able to give you 600w brand new anyway. Need to be careful with those sites for 460 wattage, if I remember correctly your model is highly overclocked and with this comes higher power usage over standard 460s.

Your current PSU might be able to handle SLI's but it's going to be close. If you have a friendly store near you they might allow you to borrow a PSU and check if indeed that is the case, or if there is an online store which will allow returns within 30 days if the product is used (not sure about this though).

[camalbitboy]

So now I'm confused. Tried individual 8800's, individual 460's and then sli 8800's and sli 460's. I benchmarked them all in Dawn of War 2 as that was one of the games I'd been having issues with.

Now I've put it back together with the 460's in sli I haven't run into any problems, even Crysis which used to crash on load works fine!

Now this would be great news except I 've noticed that the benchmarks for Dawn of War 2 for 8800GT's in sli and 460GTX's in sli give about the same frame rates!! The 460's give slightly better average but the 8800's give better min scores.

The diff between 460 Sli and non sli is minimal too, a few frames better on min frame rate in SLI.

Have I spanked £300 on graphics cards for no good reason? I'm guessing this means that I'm cpu limited so will try putting the OC back on later, and will even swap the cards back round to see if I'm getting better frame rates with a 3Ghz OC. But I'm guessing that I'll be unable to get a stable OC anyway (couldn't with 8800's or 460's) so I may be looking at a new psu anyway.

Why is it never simple?

[planet436]

How are you powering those graphics cards? The Tagan website says it has 1 6 pin and 1 6+2 PCI connectors whereas the 460s need two 6 pin connectors per card.

[camalbitboy]

How are you powering those graphics cards? The Tagan website says it has 1 6 pin and 1 6+2 PCI connectors whereas the 460s need two 6 pin connectors per card.

The tagan only comes with 2 6 pins, but has connectors for 2 more on the unit, I just had to buy the cables. The spec says it can run 4 6pin connectors.

[camalbitboy]

Psu's generally degrade by 10% per year and lowish quality psus like Tagans are unlikely to be able to give you 600w brand new anyway. Need to be careful with those sites for 460 wattage, if I remember correctly your model is highly overclocked and with this comes higher power usage over standard 460s.

Your current PSU might be able to handle SLI's but it's going to be close. If you have a friendly store near you they might allow you to borrow a PSU and check if indeed that is the case, or if there is an online store which will allow returns within 30 days if the product is used (not sure about this though).

I wouldn't consider Tagan as lowish quality, and neither do any of the reviews of their units.... I'm not claiming they are in the same league as Enermax, but def not low quality.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=149
http://www.hardwareheaven.com/review...onclusion.html
http://www.hardwareoverclock.com/Tag...ck_1300W-5.htm
http://www.pcper.com/article.php?aid...e=expert&pid=8
http://www.cluboc.net/reviews/power/...Z800/Page3.asp

Good point on the age of the unit and the fact that the 460's are stock overclocked though.

[camalbitboy]

Back to crashing with no OC on the more modern games again so gonna have to swapout the psu. After all. Prob the 850 or poss 1k Corsair so its good for the next few years unless anyone knows where to get a good price on Enermax1k's?