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Old 06-04-2013, 20:12
xmodz10
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Im going to get this motherboard

http://www.dabs.com/products/asus-m5...7T0.html?src=3

CPU will be AMD Sempron 140 which i got

and i will have two of these graphics card working to its max.

http://www.ebuyer.com/483272-his-785...i-dp-h785f1g2m

Could anyone tell me what psu is need


and if anyone could recommend me a cheaper motherboard that can take both these graphics card together
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Old 07-04-2013, 04:15
Loobster
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Use this to figure it out.

http://www.extreme.outervision.com/p...ulatorlite.jsp
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Old 07-04-2013, 05:33
neo_wales
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Your PSU will draw the power it needs so won't really 'waste' power therefore fit the biggest (power) you can afford. This way there is less 'strain' on the system when drawing power when needed.

You can pick up 750w PSUs off ebay for about 25 and no, they don't melt, burst into flames or burn your house down.
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Old 07-04-2013, 11:10
noise747
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Your PSU will draw the power it needs so won't really 'waste' power therefore fit the biggest (power) you can afford. This way there is less 'strain' on the system when drawing power when needed.
Yes and no.
I saw on a you tube video last year that if your PSU is way over powered then you could be wasting electric as it will use more power. So if you only need say 500watts and you get something like 1000watts it will use more power than it needs.

I can't find the video again, i had a quick look.

But yes in most cases as long as you don't go way over the top the machine will just take what it needs.


You can pick up 750w PSUs off ebay for about 25 and no, they don't melt, burst into flames or burn your house down.
Maybe not, but they don't seem to have the stability of higher prices ones, certainly on the 5 volt rail. I used to buy cheap ones when I was using machines in the 1 to 1.5 Ghz range, they are fine unless you push them and when you do then the machine can fail

i am not saying go for silly prices, but I would pay about 80 for a 750watt, something like a corsair builder series.

I got a thermaltake myself, but only because if was a good price
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Old 07-04-2013, 11:51
SnowStorm86
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It seems you do need to get more wattage PSU than you're likely to need, in order for the PSU to perform at maximum efficiency. The Corsair PSUs (and maybe others) have graphs on the packaging which shows power requirement vs efficiency.
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Old 07-04-2013, 12:10
noise747
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It seems you do need to get more wattage PSU than you're likely to need, in order for the PSU to perform at maximum efficiency. The Corsair PSUs (and maybe others) have graphs on the packaging which shows power requirement vs efficiency.
Of cause you do, never get a PSU that just about suits, but what I am saying is there is not need to get say a 1000watt PSU for a machine that is only going to use say 400 watts, that is a waste.

My PSU is 875 watt, I doubt my machine tops 400, so really my PSU is a waste I could have gone for say a 600watts. I got it because it was a flipping good price for a modular unit. It also gives me a bit of room to expand. I was running the machine on a 450watt PSU that was doing fine, but that was with a older video card. Not sure if it would cope now, but then again newer cards are more energy efficient.
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Old 07-04-2013, 12:17
a_c_g_t
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Of cause you do, never get a PSU that just about suits, but what I am saying is there is not need to get say a 1000watt PSU for a machine that is only going to use say 400 watts, that is a waste.

My PSU is 875 watt, I doubt my machine tops 400, so really my PSU is a waste I could have gone for say a 600watts. I got it because it was a flipping good price for a modular unit. It also gives me a bit of room to expand. I was running the machine on a 450watt PSU that was doing fine, but that was with a older video card. Not sure if it would cope now, but then again newer cards are more energy efficient.
Mind you always have a bit more than requires does put slightly less strain on the consumption and not running a psu at full pelt all the times does/could prolong it's life.

I too have a 600 watt psu probably running 400-450 watt.
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Old 07-04-2013, 12:54
Smudged
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That's quite a weak CPU to be using with such powerful graphics card(s). I wonder if it would be a bottleneck and you'd actually be better off with only one graphics card and a better CPU.

As for PSU, a quality 600 or 650 watts would be fine.
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Old 07-04-2013, 13:13
Mr Dos
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Smudged you beat me to it ! Sempron 140 + 2 gpu ? Yep bottleneck is the word. I just looked up the Sempron at

http://www.cpubenchmark.net/cpu_list.php

and it scores 716 compared to, say, an unclocked 2600k at 8503. I'd say start afresh with a modern board (and some extra fans to cope with the gpu heat). Even a 100 Intel mobo bundle would be 3X the power of that Sempron.
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Old 07-04-2013, 13:16
Dim-Star
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Use one of the power supply calculators that are available online but remember that is not the only factor to consider. Total amperage available on the +12V Rail(s) is most important, followed by the +5V amperage and then the +3.3V amperage.
Cheap PSUs are available but you get what you pay for
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Old 07-04-2013, 13:32
fmradiotuner1
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I am really happy with my

650W XFX 80 PLUS Bronze Modular Power Supply

http://www.youtube.com/watch?v=Y4GxBSmmhwA

Its running my VTX3D Black Edition Radeon HD 7870 (Tahiti LE) fine now the PC has been rebuilt.
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Old 07-04-2013, 13:41
noise747
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Mind you always have a bit more than requires does put slightly less strain on the consumption and not running a psu at full pelt all the times does/could prolong it's life.

I too have a 600 watt psu probably running 400-450 watt.
Very true, need some overhead. I wish I could find that video.

I have seen a computer that consisted of a Micro ATX board, 2Gb or ram, I think it was a I3, on board video card, hard drive and DVd writer with a 950watt PSU. Now that is a over kill.

I like my PSu in that the fan will carry on for a while after the machine switches off, so cooling it down and not letting it stay hot.


That's quite a weak CPU to be using with such powerful graphics card(s). I wonder if it would be a bottleneck and you'd actually be better off with only one graphics card and a better CPU.
I thought that, but not having really done much with Semprons lately I thought maybe they improved them.
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Old 07-04-2013, 13:41
Maxatoria
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With PSU's you need to consider how good they are at providing stable power to each device as the cheaper ones are generally ok to a certain point but once you go over a certain %age of their max load they can get erratic and you really want them to be able to stay within at worst 5% of their expected voltage and also you need to consider what will happen should the PSU die as the better ones normally have something inside them to limit the risk but a cheap one may allow mains voltage to anything connected which may cause them to blow

But workout your expected max load and add 50% to it as for most PSU's running around 2/3rd of rated power is the optimum
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Old 07-04-2013, 14:21
Grouty
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I certainly wouldn't use a 25 quid PSU, never skimp on the PSU, its probably the most important component, if a 25 PSU goes bang (which at that price is highly likely), it would take everything out with it, where as a decent one wouldn't.

Corsairs ar a great brand.
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Old 07-04-2013, 14:30
flagpole
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Corsair blow.

If it fails in warranty, but outside the first year to get a replacement you have to post it, signed for, to Holland.

which will cost you more than the cost of a new PSU. which you will need to buy anyway because the turnaround is 6-12 weeks.
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Old 07-04-2013, 14:47
d'@ve
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Problem here is that the O/P hasn't given enough information about what he wants to do with his system for anyone to help him, really. Question 1 would be why does he need 2 powerful graphics cards anyway, on such a relatively feeble system - the Sempron and the two graphics cards (and presumably 4 HD or two immense monitors) seem to be completely out of kilter, to me. What's the rest of his system like anyway? Unless he reappears and tells us more, nobody can say what PSU he needs, apart from the online specs for each graphics card (500W+ PSU).

In general though, PSU requirements are over-hyped. I have a 350W PSU powering dual HD monitors, BD writer, 6GB RAM, 3 internal HDDs totalling 3TB, AMD Phenom II 964 @ 3.5GHz and a Radeon 6570 (admittedly fanless), and have just run the following test, using a digital power monitor to measure what is being drawn by the system.

Simultaneously running:

1. Handbrake - cropping/converting HD .avi/h.264 video file to .mp4/h.264 (100% CPU)
2. VLC Player - Watching Blu Ray movie using the internal BD drive on monitor 1
3. Firefox - Watch Doctor Who on BBC iPlayer in HD on monitor 2

The conversion was successful and both HD videos played faultlessly. Core CPU temperature got a bit high but apart from that, the maximum system power drain at any one second interval was 230 Watts. My PSU is 350 Watts and I've never had a moment's problem with it (though it's not a "cheapo" and if I upgrade any more components I may get a bigger PSU at the same time).

PSU requirements for the vast majority of computer users are way over-hyped, a 500 watt PSU may or may not be sufficient for the O/P, depending on what the rest of his system will look like and the maximum drain per graphics card (which I can't see in the specs).
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Old 07-04-2013, 14:48
Sick Bullet
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Your PSU will draw the power it needs so won't really 'waste' power therefore fit the biggest (power) you can afford. This way there is less 'strain' on the system when drawing power when needed.

You can pick up 750w PSUs off ebay for about 25 and no, they don't melt, burst into flames or burn your house down.
Do not follow this advice and buy a 750 watt PSU for 25 this is the most important part of a PC one fault could wreck high end parts these cheap PSU's most be avoided, go with a Corsair CX600 or a Seasonic 600 watt+ for peace of mind seriously.

I use the CX600 one of the best PSU's around for money http://www.ebay.co.uk/itm/Corsair-CX...item53f6c59947
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Old 07-04-2013, 16:51
noise747
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I certainly wouldn't use a 25 quid PSU, never skimp on the PSU, its probably the most important component, if a 25 PSU goes bang (which at that price is highly likely), it would take everything out with it, where as a decent one wouldn't.

Corsairs ar a great brand.
Corsair blow.

If it fails in warranty, but outside the first year to get a replacement you have to post it, signed for, to Holland.

which will cost you more than the cost of a new PSU. which you will need to buy anyway because the turnaround is 6-12 weeks.
I have built over the last 4 years, 5 machines and have replaced a power supply in two others and have used Corsair in all of them and not a problem with any, most of them was only a 500watt builder apart from one which was around 800watt and a pro version.

I also think coolermaster and OCZ are fine as well.
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Old 07-04-2013, 22:43
xmodz10
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Problem here is that the O/P hasn't given enough information about what he wants to do with his system for anyone to help him, really. Question 1 would be why does he need 2 powerful graphics cards anyway, on such a relatively feeble system - the Sempron and the two graphics cards (and presumably 4 HD or two immense monitors) seem to be completely out of kilter, to me. What's the rest of his system like anyway? Unless he reappears and tells us more, nobody can say what PSU he needs, apart from the online specs for each graphics card (500W+ PSU).

In general though, PSU requirements are over-hyped. I have a 350W PSU powering dual HD monitors, BD writer, 6GB RAM, 3 internal HDDs totalling 3TB, AMD Phenom II 964 @ 3.5GHz and a Radeon 6570 (admittedly fanless), and have just run the following test, using a digital power monitor to measure what is being drawn by the system.

Simultaneously running:

1. Handbrake - cropping/converting HD .avi/h.264 video file to .mp4/h.264 (100% CPU)
2. VLC Player - Watching Blu Ray movie using the internal BD drive on monitor 1
3. Firefox - Watch Doctor Who on BBC iPlayer in HD on monitor 2

The conversion was successful and both HD videos played faultlessly. Core CPU temperature got a bit high but apart from that, the maximum system power drain at any one second interval was 230 Watts. My PSU is 350 Watts and I've never had a moment's problem with it (though it's not a "cheapo" and if I upgrade any more components I may get a bigger PSU at the same time).

PSU requirements for the vast majority of computer users are way over-hyped, a 500 watt PSU may or may not be sufficient for the O/P, depending on what the rest of his system will look like and the maximum drain per graphics card (which I can't see in the specs).

its for mining litecoins which is similar to bitcoins,

and then in a few months time turn it into a gaming pc which a better cpu
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Old 07-04-2013, 23:40
Smudged
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its for mining litecoins which is similar to bitcoins,

and then in a few months time turn it into a gaming pc which a better cpu
That makes more sense (the weak CPU was a bit confusing). Not that I really understand how that mining works. Can you really make money doing it?
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Old 08-04-2013, 00:45
xmodz10
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That makes more sense (the weak CPU was a bit confusing). Not that I really understand how that mining works. Can you really make money doing it?
yes, if there is someone willing to buy the litecoin off you for

1 litecoin currently cost $3.78 dollars
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Old 08-04-2013, 08:33
flagpole
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I have built over the last 4 years, 5 machines and have replaced a power supply in two others and have used Corsair in all of them and not a problem with any, most of them was only a 500watt builder apart from one which was around 800watt and a pro version.

I also think coolermaster and OCZ are fine as well.
I'm not saying they are any more unreliable than any other brand.

I'm simply saying, that you may not be aware, that the 3 year warranty is meaningless as to use it costs more than to buy a replacement.
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Old 08-04-2013, 08:35
flagpole
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That makes more sense (the weak CPU was a bit confusing). Not that I really understand how that mining works. Can you really make money doing it?
It converts electricity in to money.
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Old 08-04-2013, 08:39
noise747
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I'm not saying they are any more unreliable than any other brand.

I'm simply saying, that you may not be aware, that the 3 year warranty is meaningless as to use it costs more than to buy a replacement.
Like the 3 year warranty that Seagate used to have, had to send the drive back to Switzerland, i suppose at the time hard drives was pretty expensive, but it still cost me 3 times. Never buy Seagate again

Anyway, sadly this is the same for a lot of products in the computer world that you got to send the part back over seas.
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Old 08-04-2013, 08:43
flagpole
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Like the 3 year warranty that Seagate used to have, had to send the drive back to Switzerland, i suppose at the time hard drives was pretty expensive, but it still cost me 3 times. Never buy Seagate again

Anyway, sadly this is the same for a lot of products in the computer world that you got to send the part back over seas.
Shortly after i had this experience with corsair, i had to replace a logitech mouse under warranty. they just asked me to email them a photograph and couriered me a new one the next day.

So i do think it is worth informing people that there are good companies around.
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