Msi R6870 hawk and power supply questions

[Doileen]

Hi guys, I recently decided to build my own computer and I have a few questions, it was designed around a i5 2500k, here are the components:

I5 2500k oc'd to 4.5 ghz stable
Msi p67 gd53 motherboard
4gb corsair vengeance lp ram
Akasa venom 400cx heatsink with 2 viper fans in push pull
Ocz Zs series 650 w psu
Msi r6870 hawk gfx card.
500gb hdd
DVD/rw

Everything is running fine and my comp is completely stable, what I was wondering is would my psu be able to handle another r6870 in crossfire?

Also the gfx card used 2 x 6 pin power cables and my psu only has 2 of those, so if I wanted to crossfire how would I connect a second?

Thx alot for reading and I hope you can shed some light on this.

Doileen

 

[geekapproved]

You need a 700w+ if your doing any overclocking, which you are. If you were not overclocking the cpu (or gpu's), then you could probably get away with the 650w ocz.

I see no reason to overclock your cpu at all though, even with 2-6870's. Your just raising your electric bill, and creating extra heat which reduces the life of all the components in your case.

Only if you had 2 very high end video cards would you need to consider overclocking the cpu.

If you COULD use it, you would put 1x6 pin to each card, and use pci-e - molex adaptors for the secondary power on each card. These usually come in the box with the video card.

 

[Doileen]

I forget to mention I have 1 exhaust fan and one front fan in the case too. So of I put my i5 2500k back down to stock u think I could handle the crossfire? Also does the oc really use that much more power?

Thx for the reply.

 

[Doileen]

Also, does oc'ing the CPU really use that much more wattage from the psu? And don't you think the difference from 3.3 - 4.5ghz will make any kind of difference while gaming?

I am a newbie when it comes to all this kind of stuff sorry if I sound stupid.

Also I really would like to crossfire my 6870's so does anyone else think my psu would be capable? U only really see people saying corsair and antecedent are good psu's and never really see any ocz ones mentioned.

Thanks again

 

[geekapproved]

I've had ocz psu's, they are ok, your's is a newer bronze model, which is pretty decent.

A 2500K at 3.3 uses 95w. A 2500K at 4.5 uses 150w. So yes it's a difference of 55w.

 

[geekapproved]

OCCt? What's with the abbreviations lately, everyone thinks were mindreaders or something?

Using a power supply calculator, its says 155w at 4.5ghz at the stock 1.3v. If your using more voltage, that equals more watts.

What I'm telling him is the general difference, not the exact wattage. What I mean by that is your cpu's tdp is determined by the load on the cpu/gpu. If your not using your integrated gpu, those number would be less obviously.

 

[geekapproved]

Ok you know your cpu at 3.3ghz is a 95w part right? So common sense tells you that if you raise the voltage and speed it's 50% your going to see at least a 50% increase in power draw right?

Are you using your integrated gpu at 100% too?

 

[geekapproved]

Well the 2500K is rated at 95w, obviously this takes into consideration the gpu too, so power consumption without gpu should be somewhat lower.