GtX 470's SLI??

reccy

Distinguished
Jun 6, 2007
532
0
19,010
Hi Guys, just a quick noobish question, which most would find simple..

My Computer Spec's:

i7 930 @ 3.6Ghz
6gb Geil Black Dragon DDR3 (8.8.8.24 @834mhz x2)
Asus P6X58D-E Mobo
Asus GTX 470
Huntkey Titan 650W PSU
In a Coolermaster RC-600 Gladiator Case
1920x1080 Res

Now my question here today, is I want to SLI with this system as ive never done it before and also want to improve graphics in the long run seeing as all the games coming out now are looking pretty awesome.

I need to replace my PSU granted to run in SLI, and I was thinking the Cooler Master GX 750W PSU seems in good shout, but I don't know what, 80plus, 60amp on the 12v rail etc etc etc means or how to equate what power 2x 470's need going with the rest of the system etc...

Would the PSU be sufficient to run 2x GTX 470's? Is 2x GTX 470's a good build?

Also, if I did SLI these, do I have to use the next PCI-e slot or could I use the third for example (mine as 3x PCI-e slots) Just wondering for heating issues on the first GPU?

Sorry for the noobish questions..

Cheers everyone :)
 
1. 2x GTX470 are GREAT setup, i think you can maxed out almost every games at your resolution (1920x1080).
2. Coolermaster is an acceptable brand, do not cheap out on PSU, it's the most important thing inside your PC. get a quality brand like Corsair, OCZ, Antec, Seasonic, SilverStone with 750W (well, if you can afford it).
3. Cooler Master GX 750W should enough to run 2x GTX470, but just like i said before, get a higher quality brand.
4. You can use any slot as you wish, but usually people use 1st and 2nd slot.
5. Well, i think you already have a good case there, don't worry too much about heat.
 

reccy

Distinguished
Jun 6, 2007
532
0
19,010
Many Thanks for the quick reply..

2/3 - Coolermaster? I thought this was a good brand? saying that i use ebuyer.com and/or overclockers.co.uk as im based in the UK, so these seem not to stock any decent brand (for this type of setup) without spending far too much £££ - any suggestions from the site given? (again, sorry not an expert in this scenario)

4 - Was just wondering due to the GTX 470 using up 2 slots, the second gtx will be right next to it, so the heat coming from one is going straight onto the other.
 

reccy

Distinguished
Jun 6, 2007
532
0
19,010
Ahhh, i got told 650w (no matter what brand) is enough for a High End CPU/Mobo/GPU, adding an extra GPU requires 100W minimum onto the load of the PSU?

Plus that only has 2x 6pin PCI-e connectors? Not overally convident on using 4pin peripheral to PCI-e adaptors (or any adaptors to be fair...)
 


^
It has 2 x 8 pin PCI Express power.
Each GTX470 need 2x 6pin, don't worry about that, you can use molex 4pin to 6pin power connector, like this one:
PCI%20Express%204%20pin%20to%206%20pin%20power%20adapter.jpg


It's okay if you want to stay with that CollerMaster PSU, like i said before, it should run 2x GTX470 without problem.
I just suggest you a better brand. :)
 

reccy

Distinguished
Jun 6, 2007
532
0
19,010
Was on a forum somewhere, OCI?? something like that. Was an average of 150W per Component in the PC. CPU, GPU, Mobo + Ram and HDD's/Optical Drives 4x 150 = 600W. This is all high end gaming components btw as suggested on the forum.

Was explained at something like each component draws a different power comsumption and force at any given time, and that the 650W is a Max rated 100% load.. So adding any high end component to the already exsiting high end components in the system will overload the PSU no matter what make. As all PSU's are tested to some degree to enable the rating currently supplied on the PSU for health and safety rules and some law of electrical equipment..

I personally could of mis read the information, as it is going back a couple of months ago, but not sure, hense why i asked the experts :)

Something like that.
 
Of course if your PSU draws more power than the 650W then a 650W PSU will definitely fail no matter what brand. I have read reviews that the Corsair VX450W can deliver 520W of power for some time. But that would eventually break down the PSU. But that doesnt mean that the PSU is bad. Its the lack of knowledge on the user's part.

Obviously while selecting a PSU we recommend with a little bit of room left. Not PSU's which are just rated at the border.
 

reccy

Distinguished
Jun 6, 2007
532
0
19,010
According to this expert on the forum, a high end gaming system utilizes about 150 watts of power for each of the 4 main component areas on average.

CPU, Mobo and Ram, GPU and HDD's/Optical Devices. 600Watts Minimum.

So using his recommendation, a 750watt PSU is needed for 2x High End GPU's and my system. Now, ive never had a problem with a PSU, being it cheap or expensive (maybe not branded), also does the job and very well too. Even this Huntkey Titan ive got, runs my system with 4 sata hdd's, 4 case fans, optical drive, gtx 470 with no stutters.

The fact of using adaptors or spillters on a PSU, to me counts as overloading it straight away. You converting/spillting/adapting power it hasn't got to use a different source.
Meaning on that corsair, im spillting the load of 4 Molex connectors to utilize 2 PCI-e connectors. Meaning your drawing power to something it hasn't already got the sufficient power to do so as standard.

Same thing as using a car to tow a trailer which hasnt got a tow bar in the first place. Adapting the car without using whats already there made for that particular scenario.

Over thinking?? Or just being stupid? :)
 

Petey1013

Distinguished
May 6, 2010
379
0
18,810
I wouldn't go with anything less then a 750w of a GOOD brand like Corsair, Antec, Silverstone, Seasonic for SLI 470s. Your already spending a lot of video cards alone, whats another 1-200 bucks for a QUALITY PSU, which if you buy a s****y one, can fry your entire computer.

Also, What kind of case do you have? Or better yet, how many PCI (expansion) slots does it have in the back?

If you have 7 or under, you'll have to run the cards sandwiched together. Will make the top card run on avergae 7-10 degrees hotter then the lower.

If your case has 8 or more expansion slots, you can run the bottom card in the lower 8x slot, for virtually no performance hit, and both cards will run cool(relatively)
 

Petey1013

Distinguished
May 6, 2010
379
0
18,810
Yeah, so you have to run them sandwiched. Just make sure you've got some good fans in that case, its a little small with limited airflow. you NEED a sidefan too.
 

reccy

Distinguished
Jun 6, 2007
532
0
19,010
I have an exshust fan at the top back, i have an fan on the side blowing cold air into the case, the top fan is an exshaust fan also, with the blue led fan on the front of the case blowing cool air into the case over the HDD's.

So does this mean i cant use the second GTX 470 in the 3rd PCI-e slot on the motherboard?
 

Check your mobo manual, it should indicate which slots can be used for dual SLi but it is usually slots one and two.
 

reccy

Distinguished
Jun 6, 2007
532
0
19,010
Just checked the manual and it suggest that a 1000W Minimum to run in Sli Mode, 2 and above and also did a check on the PSU calulator and that also suggest around 950watts? Ive just gone and ordered the Coolmaster GX 750W as i got credit for an old item so i got 70% off.

Is this the right choice or should i cancel and order something better from them? (overclockers.co.uk)

:( Bloody computers, plug and play?? bahhhh :)
 

Guru3D had SLi'd 470's at 567w total system load so a 750w PSU should be more than enough.
 


nVidi, ATI intentionally bloat the PSU requirements. That is coz they dont wanna be blamed for it! Safe to recommend higher than optimum! :)