Crossfire Gaming, i5 or i7?

Jbutler · 1 Dec 2009 at 19:35

How much of a differance in performance is there between the i5 & i7 in crossifre? (2 5850's)

Biz.Kid09 · 1 Dec 2009 at 19:50

Well i7 can run at x16 on both lanes i believe and i5 only x8 on both, The difference i think however is not massive and the price certainly does not make up for the extra performance.

Showboat · 1 Dec 2009 at 20:16

its not i5 v i7 you need to worry about, its p55 mobo v x58 mobo.

I believe you can put an i5 and i7 into a p55 mobo, but only a i7 into an x58 mobo.

In crossfire, the p55 will only offer x4 on the second lane, while the x58 will offer x16 on both lanes.

If you really want the best from crossfire you will need a x58 mobo and i7 chip, the performance increase over a i5 and p55 mobo with one gfx card will not be enough to warrant the extra money though.

Jbutler · 1 Dec 2009 at 21:06

Showboat said:
its not i5 v i7 you need to worry about, its p55 mobo v x58 mobo.

I believe you can put an i5 and i7 into a p55 mobo, but only a i7 into an x58 mobo.

In crossfire, the p55 will only offer x4 on the second lane, while the x58 will offer x16 on both lanes.

If you really want the best from crossfire you will need a x58 mobo and i7 chip, the performance increase over a i5 and p55 mobo with one gfx card will not be enough to warrant the extra money though.

I thought it was x8 (the second lane) for p55?

DotA · 1 Dec 2009 at 21:52

I also think that it is x8 x8 when xfireing.

Jbutler · 2 Dec 2009 at 18:39

So i7 doesnt warrant the extra price compared to i5?

Legion · 2 Dec 2009 at 18:48

Jbutler said:
I thought it was x8 (the second lane) for p55?

The Second 16x pci-e slot on the cheaper P55 boards runs at 4x.

If you want an 8x/8x board the cheapest boards that offer this are the Asus P7P55D PRO,and the Gigabyte UD4.

You'd have to do your own research on other brands to see what boards in their mid-priced ranges do this.

Nameless_87 · 2 Dec 2009 at 19:01

if you really want to crossfire, have the money to spend and be more future proof I would get the i7 and an x58 board.

Should last you for a few years without the need to upgrade anything imo.

Jbutler · 2 Dec 2009 at 20:15

I forgot to add. What about AM3? they support x16 x16

MeMeMeMe · 3 Dec 2009 at 04:02

There's a review where someone compared crossfire at x16/x16 v x8/x8, and found that a difference does exist, but it's minor (less than 10% slower, often much less).

My AM3 rig was chosen to for crossfire potential among other things - the motherboard supports x8/x8; to get that on an P55 mboard I'd have to spend a bit more.

If you have oodles of money to spend, the i7 and x58 choice does seem the best bet, but if you're on a budget, i5 and am3 both have good options, and a really tight budget, the am3 mboard I chose may be the only way to go.