Good PSU?

[HostileDonut]

I do not know much about PSUs, but last I heard Seasonic was making Corsair, XFX, and Antec PSUs. Do they still make XFX PSUs? I would assume so. Here is the PSU I am looking at: http://www.newegg.com/Product/Product.aspx?Item=N82E16817207007&cm_re=xfx_650w-_-17-207-007-_-Product If it can really support 650w I am good to go.

 

[HostileDonut]

BTW, I need it to support this: ASRock AM3 870 Extreme3 MoBo, 1 ASUS x24 burner drive, 2 WD 500gb Black Caviar 6gb RAID 0 Drives, Antec 300 Illusion, 8gb PNY 1600Mhz RAM, AMD Phenom II X4 955 BE, and two hd6850s. Also, the CPU and GPUs might be OCed.

 

[jsc]

A pair of 6850's needs about 20 -22 amps. The 650 watt XFX has a 52 amp rail.

you have plenty of power available even if you are going to overclock.

 

[ko888]

I do not know much about PSUs, but last I heard Seasonic was making Corsair, XFX, and Antec PSUs. Do they still make XFX PSUs? I would assume so. Here is the PSU I am looking at: http://www.newegg.com/Product/Product.aspx?Item=N82E16817207007&cm_re=xfx_650w-_-17-207-007-_-Product If it can really support 650w I am good to go.

All of XFX's PSUs are still being OEM'd by Seasonic.

The XFX P1-650X-CAH9 650W model you have chosen has a problem in that when you exceed Seasonic's crossload specs there is excessive ripple generated on the +5 Volt rail.

The better quality choice would be the XFX Core Edition PRO650W (P1-650S-CAB9) for $9 less at $89.99. The only drawback is that it's not modular but its electrical performance is better than the model you have chosen.

A single reference clocked Radeon HD 6850 will draw a maximum of 8.75 Amps from the +12 Volt rail. A 2-way CrossFire setup with these cards would draw a maximum of 17.5 Amps from the +12 Volt rail.

The XFX 650 Watt power supply will have no problem powering your system at stock clock speeds and has plenty in reserve for any overclocking that you may want to attempt.

 

[HostileDonut]

How about this? I need the rebate. http://www.newegg.com/Product/Product.aspx?Item=N82E16817207002&cm_re=XFX_650w-_-17-207-002-_-Product Would that be good? I would get the core edition, but no rebates.

 

[hunter315]

ko888 is correct in that if you exceed the crossload it will go out of spec, but you cannot crossload it like that on a modern system, you wont be able to find enough things to load down the 3.3V and 5V rail with. Any of the XFX units are good, they all have gotten good reviews at Jonnyguru i have no issues with recommending any of them.

 

[HostileDonut]

So, would the one I wanted be fine??? What is cross-loading???? I want to make sure I am going to be very stable, and also, is the second PSU I linked better?

 

[ko888]

How about this? I need the rebate. http://www.newegg.com/Product/Product.aspx?Item=N82E16817207002&cm_re=XFX_650w-_-17-207-002-_-Product Would that be good? I would get the core edition, but no rebates.

This model is also from XFX's XXX Edition series just like the original one you chose. It has the same internal components and design. The only difference I see is with the PCI-Express Supplementary Power Connectors:

P1-650X-CAG9 has 4 x 6-Pin, 2 x 6+2-Pin
P1-650X-CAH9 has 1 x 6-Pin, 3 x 6+2-Pin

HostileDonut is right about trying to replicate the crossload problem in real-world conditions. It was just a problem that was encountered by JonnyGURU during his testing of that model.

 

[HostileDonut]

What is a crossload? Would I be doing it?

 

[hunter315]

Crossloading is when you have a really high load on the 12V rail and almost no load on the 5V and 3.3V rails or a really high load on the 5V and 3.3V rails and almost no load on the 12V rail. The XFX unit only showed an issue with almost no load on the 12V rail but since a modern system pulls most of its power off the 12V rails you will never be able to crossload it in that direction on a modern system.

 

[HostileDonut]

Okay, so that system I said will be fine, but how about this system: Antec 3 Illusion, ASRock AM3 870 Extreme3, single 500gb wd black caviar, x24 ASUS burner, single hd6850 OCed, AMD Phenom II X4 955 BE OCed, and 4gb 1600Mhz RAM.

Will there be any crossloading there?

 

[HostileDonut]

Just making sure, because after-all, the only stupid question is the one I didn't ask.

 

[hunter315]

No crossloading onto the minor rails there, the only way you can really pull it off is by running it in an older Pentium III system where most things got their power from the 5V and 3.3V rails, these days the RAM, some things on the motherboard, and the disk drives are the only things that pull power from the minor rails, but the 955 and 6850 will always be pulling wayy more power from the 12V rail than everything else gets from the minor rails, you will be fine.

 

[HostileDonut]

Okay, thanks. You know, I was really thinking, Intel P3 CPU or AMD Phenom II X4 955BE. I know the 955 will blow it out of the water, but the P3 is still good, right? JUST KIDDING!!!!!! Thanks for all the help you guys. My system will be pretty future-proof if I have the power to add another drive, 4gb RAM, and another hd6850 later. Maybe even a few more fans.

 

[unpro]

No crossloading onto the minor rails there, the only way you can really pull it off is by running it in an older Pentium III system where most things got their power from the 5V and 3.3V rails, these days the RAM, some things on the motherboard, and the disk drives are the only things that pull power from the minor rails, but the 955 and 6850 will always be pulling wayy more power from the 12V rail than everything else gets from the minor rails, you will be fine.

Does this apply even when the PC is idle or in sleep mode? I mean, wouldn't that mean it's pulling less on the 12V rail?