Will my PSU handle 2x 4870's *Thanks*

Reedweaver

Reedweaver

Reedweaver

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Will my Jeantech Storm 700w handle my system?

See my spec below in sig: PSU output table also below;

OUTPUT
Voltage
+5V +12V1 +12V2 +12V3 -12V +5Vs +3.3V
Max load
30.0A 16.0A 25.0A 17.0V 0.5A 2.5A 28.0A
Min. Load
0.5A 1.0A 1.0A 1.0A 0.0A 0.1A 0.8A
 
Yes, thats the one...budget from those boys in purple. I've been spec'd a psu from this forum in another post.

This one:

http://www.overclockers.co.uk/showproduct.php?prodid=CA-117-AN&groupid=701&catid=123&subcat=

I'm wondering if my budget 700w will run the crossfire in the meantime:

The Storm has a combined output of 700W, which is provided by three 12V rails. 12V1 is rated at 16A and powers the motherboard, CPU1 and first PCI-E plug, 12V2 is rated at 25A and powers CPU2, the second PCI-E and S-ATA plugs while 12V3 is rated at 17A and powers the Molex plugs. A 28A 3.3V rail, 30A 5V rail, 0.5A -12V and 2.5A 5VSB rail round off the specification.
 
Reedweaver said:
Can any new 700w power supply run 2x GPU cards?
Click to expand...

easily.

a really good one might even manage the power sucking monster known as GTX480 in SLI

really good makes are,

Corsair
Antec
Seasonic
Bequiet
Enermax

good ones are

Coolermaster
OCZ
Zalman
 
Reedweaver said:
Can someone tell me what the 80 plus bronze, sivler gold certified means?
Click to expand...

To go into a bit more detail. When the power supply converts electricity from AC to DC some energy is lost. So if you had a 800W PSU and you were drawing all of that (unrealistic I know), 1000W would be theoretically taken from your power socket at the wall. Realistically it's just used to see how good the PSU is at a glance. Higher rating = Better PSU = More £££ :)
its how efficient they are at 80% load, which is a common test.
Click to expand...

Oh... I thought it's how efficient it was at a certain load. 80% min being bronze and then the higher being silver and gold?
 
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AMD say you need two 75w PCI-e power connections to run a 5870. 150w at 12v equates to 12.5 amps per card (25 amps total) and that's for the 5870.

If your PSU can genuinely put out the current it claims it can you shouldn't have a problem with 4870s, providing you can tap into that 25amp rail :)
 
OK I think I need some help here still.


My PSU has three 12V rails.

12V1 is rated at 16A and powers the motherboard, CPU1 and first PCI-E plug
12V2 is rated at 25A and powers CPU2, the second PCI-E and S-ATA plugs
12V3 is rated at 17A and powers the Molex plugs.
1x 28A 3.3V rail,
30A 5V rail,
0.5A -12V and 2.5A 5VSB rail round off the specification.

In order to get the best shot at my current PSU running my spec, what do I plug in where?

What are the CPU1 and CPU2 terminals? are they the 2x 4pin that plug into the motherbaord?

This is what the back of the PSU looks like...
image022.jpg
 
If the 2x PCI-e 6pin power connectors are on different rails then I could plug one of them into each of the 2x 4870's. That would give me 1x 4870 on the 16A rail and 1x 4870 on the 25A rail. If I then used a 4pin molex to 6pin pci-e power splitter off the 17A rail and put this into each of the 2nd power slots on the cards it shoul give me power off 3x of the rails.....Does this sound like a viable solution.....

Can you get 4pin molex to 6 pin pci-e power connectors?
 
Reedweaver said:
If the 2x PCI-e 6pin power connectors are on different rails then I could plug one of them into each of the 2x 4870's. That would give me 1x 4870 on the 16A rail and 1x 4870 on the 25A rail. If I then used a 4pin molex to 6pin pci-e power splitter off the 17A rail and put this into each of the 2nd power slots on the cards it shoul give me power off 3x of the rails.....Does this sound like a viable solution.....

Can you get 4pin molex to 6 pin pci-e power connectors?
Click to expand...

sounds correct

and akasa do adaptors.

www.overclockers.co.uk/showproduct.php?prodid=CB-018-AK&groupid=701&catid=48&subcat=153
 
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I'll order 2x from Overclockers and see what happens... I cant damage/short any of my other hardware can I?

I suppose I can check how hot the wires are getting (if they do warm up)...the psu should short 1st though I guess...
 
12V1 is rated at 16A and powers the motherboard, CPU1 and first PCI-E plug
12V2 is rated at 25A and powers CPU2, the second PCI-E and S-ATA plugs
12V3 is rated at 17A and powers the Molex plugs.

12V1 is a 16A rail - Motherboard 4-6A – half of the i3 processor 3.25A, 4870 11A = 18.25A MAXED OUT
12V2 is a 25A rail - Other half of i3 processor 3.25A, 4870 11A, 3xRaptor HDDs 10A = 24.25 MAXED OUT
12V3 is a 17A rail -DVD Burner, 5xfans, fan controller = 8A so 9A to play with.

I need to take some pressure off the 12V1 and 12V2 rails…if I connect the 2nd pci-e power connector off both the 4870’s up to this rail how does the card know what power to pull from each source?

Can you even do this…
 
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