Looking at getting new PSU, likely Antec. Need help as not 100%

[mikeo01]

Antec PSUs are good, and for that price you really can't go wrong.

That's probably the best price you are going to get it for, 750W will be fine. The only thing I don't like about the power supply is the quad rails, 25A should be enough for one HD 6870, just make sure you don't overload one rail, space out your components a long different rails.

[Fjo]

The only thing I don't like about the power supply is the quad rails, 25A should be enough for one HD 6870, just make sure you don't overload one rail, space out your components a long different rails.

It's all good, the 6870 draws ~12-14A at load, and the modular cabling on that Antec puts one PCI-E 6+2 cable on the 12V3 rail and the other on the 12V4. So, whether using a single card or two in CrossFire, each card gets at least ~11A clearance.

That leaves another 25A 12V rail for drives etc., and the rest is hardwired and keeps to itself.

[D1DM]

Indeed, the Antec Truepower New TP-750 is the best 750W, modular PSU for less than ~£80. The multiple +12V rails on it are actually a good thing.
Fan speed range is 800-1800RPM.

If you're willing to go £3 over your £80 budget and potentially get a European power cord (do Pixmania still do this?) then this is a good choice:
Lepa G750-MAS (£83 @ Pixmania)
http://skinflint.co.uk/826174
More efficient, semi-fanless to 15% load. However it only has a 3 year warranty. The 650W version is £76, which is more than enough for your build and future upgrades.

[Fjo]

£83, +£8.80 for delivery, and Pixmania are a nightmare for RMA claims (which LEPA requires you to use for the first 2 years). Otherwise it's a good one. I'd still recommend the Antec from Scan of the two though.

[c12038]

It's all good, the 6870 draws ~12-14A at load, and the modular cabling on that Antec puts one PCI-E 6+2 cable on the 12V3 rail and the other on the 12V4. So, whether using a single card or two in CrossFire, each card gets at least ~11A clearance.

That leaves another 25A 12V rail for drives etc., and the rest is hardwired and keeps to itself.

Where do you get this info from "6870 draws ~12-14A at load" as i would love to know as each site i have visited per review and hardware listing states (28A and min 500w PSU)
if the op goes and buys a PSU based on info you gave him and has problems do you think that would be fair....

The community in general have explained to the OP that in order to have a fully functional system and having no problems he requires at least a PSU of 750w with a good single +12v Amp rail system rated at around 40 - 60A......

All i am going to say is too the OP go with what you think is the correct advise and not listen to dribble.........


Also here is a guide to buying a PSU and what you need to look out for http://www.kitguru.net/components/po...-buying-guide/ have a read then make your own mind up

Also another guide http://www.computerforum.com/186629-...ech-guide.html read this as well

[Fjo]

Where do you get this info from "6870 draws ~12-14A at load" as i would love to know as each site i have visited per review and hardware listing states (28A and min 500w PSU)
if the op goes and buys a PSU based on info you gave him and has problems do you think that would be fair....

The community in general have explained to the OP that in order to have a fully functional system and having no problems he requires at least a PSU of 750w with a good single +12v Amp rail system rated at around 40 - 60A......

All i am going to say is too the OP go with what you think is the correct advise and not listen to dribble.........

You're going on AMD's recommendation, which is based on a whole system, is a ballpark figure, is more than many people will need and is suggested in an attempt to make sure people are clear of their minimum requirements - regardless of PSU brand, quality or distribution over the rails. The sites you've visited are quoting those original, basic recommendations.

In reality, a 6870 needs two 6 pin power lines attached. Each 6 pin PCI-E cable provides 75W from a 12V rail (single rail PSU or multiple, it largely doesn't matter, and your insistence otherwise is preference at best, fallacy otherwise). 75W x 2 is 150W load draw for a 6870, at 12V that means the amperage is 12.5A per card.
The Antec PSU OP has found has 25A available per graphics card, as i've explained above - which is ample.
Add the facts that otherwise there is plenty of power supplied by the Antec, there are plenty of safety and stability measures in its construction (it's made by Seasonic), the overall build quality is good, the warranty is good, it's modular, Scan have it in stock for a good price, and that the power it supplies is steady, free from fluctuation and efficiently provided (again, it's made by Seasonic), the Antec OP has been considering is not only sufficient for his needs, but pretty much the best PSU suggested thus far in this thread.

Now, each time you've commented on a PSU related thread, c12038, you've suggested the same OCZ ZS power supply you've bought or one from the same range but at a different wattage. These aren't bad supplies, and are better than most, but just aren't the same quality as Seasonic built - but then most aren't, not quite - and your knowledge seems largely based on personal opinion or is just basically lacking, yet you've the gall to call out others for providing answers. We're all here trying to help, not just you.

The Antec True Power (New) 750W is an excellent PSU and would serve Cumminsc9 very well.

[Cumminsc9]

Well. Thats a discussion I never saw coming. However its a great load of information and well thanks to you all.

Looks like I'll be getting the Antec True Power 750W. Least I have a decent warranty and a nice PSU thats gonna last me for long enough with a good enough power supply. Now all I have to do is wait for it to turn up and get down to business with my cable management.

Thanks once again to all those who posted. Many thanks
Tom

[Fjo]

It happens, there's always room for disagreement regardless of the subject but i've no doubt anyone responding to requests for help here and most elsewhere have anything but the best intentions.
Good luck with sorting your PC out, and happy gaming.

[kalniel]

Yeah, it's called a discussion forum for good reason

For what it's worth, I agree with Fjo - I think it's factually incorrect to say the Hexus community would recommend 40-60A on the 12V for something as small as a 6870. The community are largely very good at not overspecifying PSUs, though we have one or two members with contrary opinions.

Over-specifying a PSU isn't really a problem, but it costs you both upfront and in efficiency. Modern PC components really are very efficient.

[scaryjim]

To insist on absolute factual accuracy, a 6870 could theoretically (staying within PCIe specification) draw a total of 225W (18.75A) from the 12v rail of a PSU (it can get 75W(6.25A) from each 6pin connector, and another 75W from the PCIe slot). But theoretical power draw is actually meaningless in this case.

Let's look at a real world situation. When the Radeon 7000 series came out, Hexus switched their test platform from a power-hungry high end i7 980X platform to an i5 2500k, so it more accurately represented the type of system most enthusiasts would be using. So if we look up the power draw of that system with a 6870 on board we'll get an actual, real world power draw figure that will very closely reflect the draw you're likely to see during gaming. That figure? 187W. That's for the whole system, at the wall. Even assuming a very (90%) efficient PSU, that's only 170W DC draw from the PSU. A 750W PSU would be able to run four such systems.

Realistically, adding a second 6870 then overclocking everything as far as possible under water is unlikely to do much more than double your power draw: I'd be surprised if you could get your system to pull much over 400W. A 750W PSU is really overkill, in terms of pure draw. Where it might bother you is in efficiency.

Now, a PSU is most efficient at around 50% draw, perhaps a little more, so getting a 750W PSU might sound perfect for a 400W system. However, modern computers are very good at not using power without good reason. That i5 2500K/6870 rig that pulled 187W at gaming load, only pulls 43W at idle (again, at the wall - less than that from the PSU) - and when you're browsing the web, watching videos, typing essays, sending emails, your computer is idle. PSU efficiency tends to be pretty poor below 10% draw, and most of the time you computer would be drawing < 10% of the peak output of a 750W PSU, and perhaps as little as 5%. Having an overpowered PSU in that situation could cost you a fair bit in extra electricity. On the other hand, running a PSU near full capacity doesn't drop the efficiency curve off anywhere near as badly - any 80+ certified PSU will be at least 80% efficient at 100% load: something you can't be sure of at 10% load. So really, it a matter of choice whether you'd rather have your computer most efficient at load, or at idle. There are good arguments in favour of getting a 750W PSU, but you certainly don't need one, and there are reasons to go for something "smaller". At the end of the day, though, it really comes down to what you're happy with. Make sure you get a good, reputable brand and you're unlikely to be disappointed.

[Colquhoun]

I didn't read everything in here, but I used this exact PSU in a build for a friend recently. 100% quality PSU for the price. If you need 750w, go for it.

[AlexGTR]

I would go for a corsair everytime. They are one of the only PSU's that actually give out the amount of power they are rated at.

[kalniel]

I would go for a corsair everytime. They are one of the only PSU's that actually give out the amount of power they are rated at.

Don't Seasonic, Antec, XFX, NXZT, Enermax, EVGA, OCZ or Silverstone then?

[Fjo]

Don't Seasonic, Antec, XFX, NXZT, Enermax, EVGA, OCZ or Silverstone then?

Why check or acknowledge as much when you've already decided for yourself, eh?
Easier just to repeat the name of your favourite brand, because.

[TheLazyOne]

Corsair 500 Watt CX500 V2 Builder Series 80 Plus Power Supply