Confused about the capabilities of power supply

[texasassassin]

I just recently ordered and received this power supply:

Topower TOP-1000WG 1000W:
http://www.newegg.com/Product/Product.aspx?SID=eiSjhFD6EeKjxDoMloNEXAsBl6_UhhM3_0_0_0&AID=10440897&PID=1225267&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-cables-_-na-_-na&Item=N82E16817342041

and im confused about why they would make a power supply that can produce a 1000 watts but only allow 19a for peripheral devices.

According to this review from tweaktown:

http://www.tweaktown.com/reviews/4178/topower_top_1000wg_1000w_power_supply_review/index4.html

It states: "12V1 handles the 20+4 pin Main connector and all of the peripheral connectors." So basically from what i can gather, my video card and any other devices i hook up will be drawing off the same 19a rail. So the video card i have now requires 24a or above, so theres no way i could do sli with this power supply let alone power what i have now from what i understand. Why would they split it up like that? I will never use the other connectors that are allocated to the other rails, so essentially is it a waste of capabilities?

Should i return this one and find a power supply that has all the amps on one rail instead of split up so pointlessly?

 

[chesteracorgi]

No, you misread the Tweaktown article. There are 4 12 V rails that split the power and the mobo and peripherals (excepting PCI-E) run off the first rail, The other rails handle all of the PCI-E for your video cards.

Personally, I'd never buy a Toppower PSU. I like single 12V rail models and better reliability. I stick with PC Power & Cooling, Corsair, Antec, Seasonic, X-Clio, OCZ, Cougar and Lepa.

Your Toppower is not a bad unit, but it is not top of the class either. If you want to return it get the 950 W PCP&C. It is a great PSU and I've run one for about two years now. It also has a 7 year warranty.

 

[texasassassin]

No, you misread the Tweaktown article. There are 4 12 V rails that split the power and the mobo and peripherals (excepting PCI-E) run off the first rail, The other rails handle all of the PCI-E for your video cards.

Personally, I'd never buy a Toppower PSU. I like single 12V rail models and better reliability. I stick with PC Power & Cooling, Corsair, Antec, Seasonic, X-Clio, OCZ, Cougar and Lepa.

Your Toppower is not a bad unit, but it is not top of the class either. If you want to return it get the 950 W PCP&C. It is a great PSU and I've run one for about two years now. It also has a 7 year warranty.

Ok i see now, i did misread it but that still means the video card can only draw 19a then right?

I still have 28 days to return so i will definitely keep that in mind. Thanks.

 

[texasassassin]

So what would be the highest performance video card i could get that would also work with this psu? Would a gtx 670 work on it? I don't mind the brand but i figured by buying a 1000w psu i could run any video card i want, now that doesnt seem to be the case.

 

[geofelt]

A video card can draw power up to 75W(6.25a.) from the pci-e slot.
Then each 6 pin pci connector can supply up to 75w. and each 8 pin connector can supply 150w(12.5a)
Most of the time, it will be less.
So only the most robust set of multiple high powered graphics cards will come close to using all your psu has.
Here is a handy chart on psu needs for various graphics configurations.
It assumes a normal complement of cpu and peripherals:
http://www.realhardtechx.com/index_archivos/Page362.htm

As to quality, I think your psu is a tier 3 unit on this list.
You mostly get what you pay for:
http://www.eggxpert.com/forums/thread/323050.aspx

Virtually every psu actually has only one power generating rail. The presence of 12V1/V2... etc is a artificial UL safety thing.
You can safely ignore rails as a selection criteria.
If a quality psu has sufficient 6 and 8 pin pci-e connectors for your video cards, then it should be able to do the job.

Your GTX670 would happily run on a quality 500w psu.
It is not wrong to overprovision a bit, either for future expansion, or quieter running.
A psu will only consume the wattage demanded of it.
One negative to a overly strong psu is that it will loaf and be inefficient.

 

[chesteracorgi]

First: V X A = W. So if you have a 12 V rail rated for 19A = 228W. If you connect the GTX 670 to two 12 V rails (for 456 W) you should be fine. The minimum recommende4d draw on the GTX 670 is a 12 V @ 30 A. Your two rails will produce 38 A.

I prefer single 12 V rail models because you don't have to ballance loads and they are generally (not universally) better quality. I run two GTX 470 cards off my 950 W PCP&C PSU and have no issues for over a year and a half. Because of the lower power reqs of the GTX 670 I think that you are over building your rig. This is fine. But I'd spend the little extra on the PSU ande stick with Corsair., Seasonic, PCP&C, or other top line PSU OEM.

 

[texasassassin]

Best answer selected by texasassassin.

 

[texasassassin]

A video card can draw power up to 75W(6.25a.) from the pci-e slot.
Then each 6 pin pci connector can supply up to 75w. and each 8 pin connector can supply 150w(12.5a)
Most of the time, it will be less.
So only the most robust set of multiple high powered graphics cards will come close to using all your psu has.
Here is a handy chart on psu needs for various graphics configurations.
It assumes a normal complement of cpu and peripherals:
http://www.realhardtechx.com/index_archivos/Page362.htm

As to quality, I think your psu is a tier 3 unit on this list.
You mostly get what you pay for:
http://www.eggxpert.com/forums/thread/323050.aspx

Virtually every psu actually has only one power generating rail. The presence of 12V1/V2... etc is a artificial UL safety thing.
You can safely ignore rails as a selection criteria.
If a quality psu has sufficient 6 and 8 pin pci-e connectors for your video cards, then it should be able to do the job.

Your GTX670 would happily run on a quality 500w psu.
It is not wrong to overprovision a bit, either for future expansion, or quieter running.
A psu will only consume the wattage demanded of it.
One negative to a overly strong psu is that it will loaf and be inefficient.

Great reply, exactly what i needed to know. Great information, Thanks.