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Different sapphire HD5770 in crossfire?

Last response: in Graphics & Displays
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February 26, 2011 9:33:50 AM

Hello,

Im looking to buy a 2nd sapphire ATI 5770 for cross fire.

My first card looks like this one:
http://www.xgcdb.com/cards/sapphire/radeon-hd-5770-1gb-...

But i've noticed sapphire made different hd5770 models (not incuding flex/vapour)..

Such as this one:
http://www.techfuels.com/latest-hardware-news/22425-ati...

(there is also another different looking card)

Can my card crossfire with that one? or must it look exacly the same as my current card?

Thanks
February 26, 2011 9:49:38 AM

you can mix the brand. also you can mix card with different amount of memory but i think you might want to avoid that. get the one that have the same amount of memory with your card because if not you'll be wasting the extra memory the other card have with it
February 26, 2011 9:59:05 AM

i cant find any spec differences between the cards.... only that they look different..

Sorry im new to all this
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February 26, 2011 12:27:21 PM

Ideally match:
- RAM size
- RAM type GDDR5
- RAM speed 4800 Mhz
- GPU Core speed 850 Mhz

If you don't match them, the faster card will slow down to match the slower one.... (kind of a waste....)

Or, if you don't match the RAM size, you'll only work with the amount of RAM on the smaller RAM size card... (again a waste....)

What I would point out about Crossfire (or SLI for that matter) is HEAT. The top card in the pair will run Hotter. Between 10C and 15C hotter than the bottom card. So, be sure you have some good ventilation in your case.

You current card dumps most of the heat inside the case. (I have a pair of Sapphire Vapor-X 5770's in crossfire. And while they are cool running single cards, they dump a lot of hot air inside the case, just like yours)

The other card you show vents most of it's heat Outside the case (which will help keep things cool). And the fans on each card don't line up, so, they won't both fight each other for air from the same point. This card would be a better choice for you to keep things cooler...

And finally, you'll need a good 650 watt power supply.....

CrossFire cards must only be from the same "family" in you case you Could pair:

For : "57xx family"
- 5770 with 5770
- or 5770 with a 5750 (odd, but it would work...)

Same for : "58xx family"
- 5870 with 5870
- or 5870 with a 5850


Only thing you Can't do, pair a 57xx card with a 58xx card ......

February 26, 2011 12:30:24 PM

ok, i got it now, must be the same family. ideally the same card... although even with the design differences in the sapphire cards i showed, there is no performance difference?

Im also looking at a power supply that would support it, been looking at ocz and be quiet.

Any other brands i should put into consideration? (at a reasonable price)

And thanks for the help
February 26, 2011 1:35:16 PM

Your 1st link is to a GPU 850mhz, 1Gb RAM @ 4800Mhz

The 2nd link shows no specs, but, that fully enclosed plastic shroud is a reference card design. They run at the same speed listed above. (only those with fancy fans & coolers can run faster than that...)


Check this list of 5770's

http://www.newegg.com/Product/ProductList.aspx?Submit=E...


A quick scan shows:

- GPU speed, most all are 850Mhz (some are 875Mhz & 900Mhz)
- RAM speed, most all are 1200Mhz (due to with of buss sometimes listed as 4 times this...)
- again some are 1250Mhz

I'd go for the HIS for price and cooling on this list.....


For a power supply, you need a good 650watt supply for a pair of 5770's.

Antec, Corsair, SeaSonic, Thermaltake or Cooler master.....

$50 to $80 on sale.....

Be sure it has at least a 120mm fan on the bottom... The Corsair is dead silent (I have one...)


http://www.newegg.com/Product/Product.aspx?Item=N82E168...

or

http://www.newegg.com/Product/Product.aspx?Item=N82E168...



Let me know what Case you have for your computer (send a link). Is is a top mount or bottom mount power supply? And need to know sizes & number of exhaust fans (two cards generate a lot of heat...)


February 26, 2011 2:00:48 PM

hello,

Thanks for the reply.

I currently have a cooler master G lite case.. (not exacly top stuff)..
http://www.pricebat.us/cooler-master-glite-341-rc-341c-...

Top mounted PSU, got a fan at the back and front, and one on the side directly pointed to my i7 processor...
Next to the graphic cards is quite a large opening, im assuming thats to let hot air out?

I think i'd rather keep with same brand in terms of graphic cards... so sapphire in this case.
As for the PSU, is 650W more then enough or would it be a safer bet to go for a 750W PSU?

Using CPUID Hardware monitor, my 5770 seems to peak at 40 degrees celcius (MAX)

February 26, 2011 2:16:43 PM

also been looking at the OCZ modXtreme PRO 700W ATX if its any good.
February 26, 2011 2:24:16 PM

This seems to be your case:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I'd go with a fan at the front blowing cool air in and across the graphics cards....

Leave the one at the back. But the one on the side you might try running without it once you get the new power supply and 2nd video card installed.

Basically cool air in low at the front and hot air out high at the back.... (as hot air rises...) So that side fan might disturb this natural flow.

One note: with a top mount power supply with it's own fan mount on the bottom the Power Supply will suck a lot of hot air from the CPU and heat from the GPUs THRU the power supply. While this isn't a bad thing the power supply runs a bit hotter.

In a case I have with top mounted power supply, an Antec True Power 650watt :
- the power supply is dead silent with a single 5770....
- but, when I added a second 5770 the extra heat form the car caused the fan on the power supply to run Much faster and thus louder.

NOTE: I changed to a case with bottom mounting for the supply where the power supply pulled in cool air from outside the bottom of the case and runs silent again. So while you don' t need a 750watt supply for the power, it will likely run quieter in your top mounted case.....



February 26, 2011 2:33:33 PM

ok thank you for your input.

I shall start with getting my hands on a new power supply followed by a sapphire hd 5770, if heat is a big issue i shall consider a new case with bottom mounted PSU.

Again, thanks for the help.
!