PSU Requirements

I am wondering if FSP Group (Fortron Source) AX500-A ATX12V 500W Power Supply - Retail ( http://www.newegg.com/Product/Product.asp?item=N82E16817104934 ) is enough for a dual opteron 175, possibly overclocked some (not much).

I am planning on using a XFX 7800GTX card. Later (once the price drops a lot) I may add a second one for SLI. There will be initially 1 250GB SATA drive and potentially one or two additional drives added later on. 2GB RAM initally with an eventual upgrade to 4GB.

The cooling will be a stock heatsink with a possible fan upgrade and in addition anywhere from 20-50 watts of fans.

Edit:
If the power supply cannot handle the load I am looking for alternatives such as the SeaSonic 600W. $150 max limit, perferably something available from newegg.

If you are thinking of running two 7800's I would go to the 550watt Fortron or the 550watt Sparkle SLI. (The Sparkle is just the SLI version of the same PSU) They are $82 and $84 at eWiz. You might also consider the the OCZ 520watt Powerstream.

would the 550 be enough with multiple hard drives and other components?

I believe so, but I would defer to the opinion of Oklahoma Wolf. He is the guru of the PSU's around here.

the FSP550PLG-SLI is the one to go for. The non-sli (FSP550-60PLG) doesn't have the SLI connectors. It will handle SLI and just about whatever else you want. 36A on the +12v rail, is very nice.

The OCZ 520w Powerstream SLI will also work. It's only rated slightly lower on the +12v (3A lower) but is somewhat quieter. Do not go for the 600w Powerstream.

for me something that can take some power fluctuations would be very useful (small voltage drops, etc.)

http://www.ocforums.com/showthread.php?t=426711
There is the full list of parts that will be in it initially, the dual video card/extra memory/extra drives are months away, but I would rather not have to buy another $100+ PSU.

Both the OCZ Powerstream 520w or the Sparkle FSP550PLG-SLI will handle that, no problem.

Sparkle can be found at newegg for 109.

Jared555 said:

I am wondering if FSP Group (Fortron Source) AX500-A ATX12V 500W Power Supply - Retail ( http://www.newegg.com/Product/Product.asp?item=N82E16817104934 ) is enough for a dual opteron 175, possibly overclocked some (not much).

Click to expand...

I doubt it. I would also not run any Seasonic S12 on a dual CPU system. Fortron has just released a line of quad 12v units made specifically for rigs such as this however:

http://www.directron.com/fsp60080glc.html
http://www.directron.com/fsp70080glc.html

These will power dual Opterons and SLI. The only difference between the two is the 700w has a combined 50A 12v limit while the 600w has a 44A limit. Either should power your proposed rig. Not sure you can find these at Newegg yet being brand new, but they're due to be released as the Epsilon line before too long. They're also a whole lot more efficient than the older 550w units, though the PLG or PLG-SLI will run that rig too.

http://www.fsp-group.com.tw/english/1_product/2_detail.asp?mainid=2&fid=54&proid=155

Oklahoma Wolf, this is the powersupply on the fortron website, the 600w. I thought quad rails were poor for a destop PC and were more oriented for a server enviornment...

Oklahoma Wolf said:

I doubt it. I would also not run any Seasonic S12 on a dual CPU system. Fortron has just released a line of quad 12v units made specifically for rigs such as this however:

http://www.directron.com/fsp60080glc.html
http://www.directron.com/fsp70080glc.html

These will power dual Opterons and SLI. The only difference between the two is the 700w has a combined 50A 12v limit while the 600w has a 44A limit. Either should power your proposed rig. Not sure you can find these at Newegg yet being brand new, but they're due to be released as the Epsilon line before too long. They're also a whole lot more efficient than the older 550w units, though the PLG or PLG-SLI will run that rig too.

Click to expand...

Thanks, two questions, is the input amperage lower because of efficiency? Also, what does the PSU type EPS mean? I have seen all the different types (EPS, I think SFX, etc.) and have no idea what they mean.

Edit: also: why is 5 volts * 36 amps = 180 watts when it says 155 max on 3.3 and 5 volt? Also the 12 volt at 720 watts when the combined shouldn't be above 680.

ckj said:

I thought quad rails were poor for a destop PC and were more oriented for a server enviornment...

Click to expand...

This being a dual Opteron setup, each CPU would get its own power source on the quad units - 12v1 and 12v2. For dual rigs, I usually recommend against dual 12v units due to them having to power both CPU's from 12v2 - the S12 600w and Fortron FSP550-60PLN might have the guts to do it being rated for 18A on both, but overclocking might start bringing them down. No such problem with the quad units, or the big single 12v designs.

These new Fortrons are better than 80% efficient - they will need less power to do rated wattage than something less efficient. EPS stands for Entry Power Supply - they're server units. The line actually starts at 550w, but I haven't seen that one anywhere yet.

The 4 12v lines are likely set up to enable some to reach the whole 15A rating if others are not being as loaded. I have the PDF's of both on my hard drive - they tested them as being fully loaded in one instance at 15A+15A+7A+7A for the 600w and 15A+15A+10A+10A for the 700w (they have a chart listing several full load conditions). The last two numbers are probably for the two PCI-E connectors (12v3) and drives (12v4). I'll go see if I can find the links to the PDF's again so you can see what load levels Fortron tested them at.

Edit - 700w spec sheet, Epsilon version: http://www.home2000.net/client/fspgroupusacom/images/FSP FX700-GLN.pdf

600w, Epsilon version: http://www.home2000.net/client/fspgroupusacom/images/FSP FX600-GLN(SPEC).pdf

Will it fit in any ATX case?

Also, what would the recommended layout be for loading it with the initial hardware listed (a fan controller with 20-30 watts of fans) and then also how later on with additional drives/video card?

They will fit in an ATX case - they seem to be standard ATX size.

Ideally, the dual CPU mainboard you choose will have an 8 pin EPS connector - 12v1 and 12v2 will go to it and you shouldn't have to worry about setting that up. 12v3 should be the PCI-E connectors - just plug one in. 12v4 is for drives, and again you shouldn't need to worry about that other than just plugging drives in. Every last drive molex on there should be 12v4 - fans and fan controllers will go there too unless you mod the unit and void the warranty.

Don't worry about the low combined 3.3v/5v limit - you won't come close to loading those two down.

http://www.newegg.com/Product/Product.asp?item=N82E16813131524

This is the motherboard I am looking at.

Is there any easy way to monitor the loads on the power supply? I saw one case/psu combo that had that option but never on a regular power supply.

That's a single CPU board - did I misunderstand the planned rig? If only going single CPU (single or dual core), I'll recommend against the quad 12v units and point you in the direction of the OCZ PS520, FSP550-60PLG or FSP550PLG-SLI talked about earlier. The S12 600w will work too.

You can still use the quads, Fortron specifies 12v1 and 12v2 can take a no load condition (and I'm counting on that when mine gets ordered in a couple weeks), but it wouldn't be the best option anymore. 12v3 and 12v4 need to have a load on them.

Best way to monitor voltages is with a multimeter. There's no way to monitor current draw on each rail without spending some serious cash.

I said dual core opteron 175. Why would the 12v1 and 12v2 be unloaded?

You said "dual opteron 175" - my brain jumped to the conclusion you were running two of them

I completely forgot the 275 would be the dual CPU equivalent.

Anyway, 12v1 would still be loaded but 12v2 wouldn't. Or vice versa. You'd be using 3 of the 4 rails, and they'd be minimally loaded unless you had a bunch of drives and/or SLI. Not really a big problem, as minimum load is 0A+0A+1A+1A for the 4 12v lines, but you wouldn't actually have any pressing need for these units. If you want one because of them being more efficient, by all means grab one (that's why I'm grabbing one of the 600's for my next build). But if the big single 12v units recommended are more attractive to you, they will have no problems with the rig in question and none of the main rails will go unused.

the power supply I was looking at ( http://www.newegg.com/Product/Product.asp?item=N82E16817104934 ) only had 2x 15 amp 12 volt so that shouldn't be a problem. The main reason I am looking at the ones on newegg/directron is I have delt with both companies before, monarch is also another company I am going to be ordering parts for on this system (the processor).

Are there no molex connectors on 12v1 and 12v2? I figured there would be since not everyone would be loading it the same way. If not is there any kind of an adapter to put load on those rails? (I could probably find a way to load them down sooner or later, I have a couple SCSI drives that might be useful) plus shouldn't you load two different rails in SLI?

Sorry for all the questions.

On a dual 12v unit, 12v1 will have all the molexes and PCI-E connectors while 12v2 is solely for the CPU connector (4 pin 12v). On the quads, 12v1 and 12v2 are only for both CPU's - neither have molexes. 12v4 has all the drive molexes and will have more than enough power (especially if 12v1 or 12v2 has no load) for drives and fans - no modding needed there.

If you're going SLI, I recommend against the AX500-A. It doesn't have the power for that kind of load plus overclocking. It will run the rig you propose if going with a single video card though.