Advice on first rig build

[kevinm]

Hiya guys,
After reading threads on this site for a couple of weeks, I decided to try my hand at mining. I have no experience with computer building and I really struggle understanding code/script. That said, I decided to build a rig and have just about got it completed. see link to photo below: sorry I dont even know how to upload the photo here    If someone could explain how to upload it here, perhaps I can edit the thread to make it more readable.

 http://s1279.photobucket.com/user/Batamminer/media/IMG-20130413-00158_zps79c879ba.jpg.html?sort=3&o=0

The hardware spec is as follows:

ASUS P8Z77-V-Pro mobo
Crucial 8GB DDR3 RAM
Intel core i3-3220-3.3Ghz CPU
Seagate 500GB Barracuda SATA3 HDD
Coolermaster 1300W Silent Pro 80 Gold PSU
3 X Sapphire ATI 7970 3GB GPU's
Windows 8 OS

I have ordered some PCI-e 16x extender cables from e-bay (the mobo has slots for 3 x 16x extenders).

My questions are:

1     Will my PSU give me enough power to allow me to add a 4th 7970 card? (I have had a little windfall and can now afford another). I understand that I will need to use a 1x extender so will have to order from the net.

2     Is Windows 8 OK for an OS or should I swap it (unopened as yet) for Windows 7?

3     What hash rates can I expect from this set up for BTC & LTC mining?

Thanks in advance   

Kev

[DrG]

Very nice for somebody who has never built a rig.

The PSU should be able to handle 4 7970s doing BTC no problem, especially if you downclock the RAM to save power & Heat.  LTC on the other hand uses high memory clocks and a moderate core overclock, so 1300 should handle it, but don't CPU Mine.

I would suggest getting powered riser/extender so you're not pulling so much power through the motherboard.  The cards will pull 12v current up to 75W I believe through each PCIe slot, so you should add 1 or 2 powered risers to be safe.

Haven't tried Win 8 for mining so I can't comment.  Win 7 works perfectly fine for me.

[kevinm]

DrG,
Thanks for that advice,

This is a dumb question, im sure of that   

If I use a PCI-e 1x molex powered extender cable, where do I connect it to the power supply? since I wish to add a 4th card, the power supply to this will take up the last remaining 6 pin socket on the back of my PSU or does the power for the GPU come through the molex and i do not need to connect the power cable to the 2 x 8 pin connectors on top of the card?

P.S  I have 2 x 4 terminal molex - 1 x 8 pin power connector cables that came with the GPU's. should I plug this in the back of the PSU and then just connect the molex plug&socket to the riser cable and do away with the power supply to the top of the card?

Thanks

Kev.

[Vod]

3     What hash rates can I expect from this set up for BTC & LTC mining?

I get about 550Mhash/sec from my 7970s.  650 if overclocked.