4890 Crossfire on a P45...? Now with benchmarks! Hooray! - Page 3 - Overclock.net

rico2001 · 08-06-09

Quote:

Originally Posted by tipsycoma

Nice review but frankly, you're proving basically the same thing that tweaktown said. There is bottleneck at x8 CF 4850s. So imagine 4890s. It's basically twice as powerful as a 4850.

What???

I'm actually saying the very opposite of what tweaktown is saying.
If you agree a 4890 is twice as fast as a 4850, you did see both me and the other guy were using a 4850 X2 ran at (me:8x and him:16x) in one slot and a single 4850 ran at (me:8x and him:16x).

Geez this is getting old. I'm really not convincing many, no matter what I say or show people. The "tweaktown" myth on the net is too hard to break.

rpm666 · 08-06-09

That board isn't going to truly slow down those cards - might as well tell him he needs to go i9 to avoid any bottlenecks.

And yes, if I went i7 or HAL9000 I wouldn't have a bottleneck.

Phil_Boggild · 08-06-09

Crumbs. It really looks like the only way I can be certain is to buy the cards and test them out for myself, but that's an expensive dice to roll. If I can be sure of no PCIe bandwidth issues with sticking to one slot then it seems like the more sensible option, but GAAAH, I want those 4890's.

Rico, thank you SO MUCH for your input, you've obviously put a lot of time and effort into this very subject, and I bet you must be sick of people asking you about it by now, so I really appreciate it. Your findings are very persuasive, especially considering that you do your testing with not just the same chipset as me, but the same exact board.

Here's another angle. PCIe bottleneck or not, which configuration would be faster for me, a single GTX295 or two 4890's? The 4890's as a pair outperform the 295 in the majority of things at high resolutions, even Crysis. If, regardless of any bottleneck that may or may not be present at 8x8x, the 4890's in Crossfire are still faster than a 295 at 1920x1200, they're still the better option.

almighty15 · 08-06-09

Quote:

Originally Posted by Phil_Boggild

Crumbs. It really looks like the only way I can be certain is to buy the cards and test them out for myself, but that's an expensive dice to roll. If I can be sure of no PCIe bandwidth issues with sticking to one slot then it seems like the more sensible option, but GAAAH, I want those 4890's.

Rico, thank you SO MUCH for your input, you've obviously put a lot of time and effort into this very subject, and I bet you must be sick of people asking you about it by now, so I really appreciate it. Your findings are very persuasive, especially considering that you do your testing with not just the same chipset as me, but the same exact board.

Here's another angle. PCIe bottleneck or not, which configuration would be faster for me, a single GTX295 or two 4890's? The 4890's as a pair outperform the 295 in the majority of things at high resolutions, even Crysis. If, regardless of any bottleneck that may or may not be present at 8x8x, the 4890's in Crossfire are still faster than a 295 at 1920x1200, they're still the better option.

Will your 4870 run in the second slot or does it have to be in the first one?

If it works in the second slot then it'll be running at x8

So run tests with the card in the first slot at x16

Then stick the card in the second slot running at x8 and run the same tests

Compare results and work out weather you think CF 4890s will bottleneck

tipsycoma · 08-06-09

Quote:

Originally Posted by rico2001

What???

I'm actually saying the very opposite of what tweaktown is saying.
If you agree a 4890 is twice as fast as a 4850, you did see both me and the other guy were using a 4850 X2 ran at (me:8x and him:16x) in one slot and a single 4850 ran at (me:8x and him:16x).

Geez this is getting old. I'm really not convincing many, no matter what I say or show people. The "tweaktown" myth on the net is too hard to break.

I must not have read it right. It's hard to decipher where things are exactly. I'll take a look at it again. And OP, why would you even buy two 4890s? You have a 4870 already that is basically neck and neck with the 4890. Just buy another one and overclock it, and you'll see very similar framerates.

Phil_Boggild · 08-06-09

Quote:

Originally Posted by tipsycoma

And OP, why would you even buy two 4890s?

Because I can, my friend. Because I can.

Would running my 4870 in the second slot really bump it down to 8x? If so, I'll run benchmarks and report back.

tipsycoma · 08-06-09

Quote:

Originally Posted by Phil_Boggild

Because I can, my friend. Because I can.

Would running my 4870 in the second slot really bump it down to 8x? If so, I'll run benchmarks and report back.

Haha alright man, talk about cost effective.

almighty15 · 08-06-09

Quote:

Originally Posted by Phil_Boggild

Because I can, my friend. Because I can.

Would running my 4870 in the second slot really bump it down to 8x? If so, I'll run benchmarks and report back.

It would drop it down to x8 but it depends if your motherboard will allow it to as most boards dont like running the primary card in the second slot.

Just plug it in and try it, GPU-Z will tell you if its running at x8 aswel

Brutuz · 08-06-09

What I say about it is don't care, just do it anyway, upgrade your motherboard to one with 16x/16x later on if you want and then if you see a difference, good for you.

Especially since a single HD4890 can practically max nearly any game at 1920x1080 (My res), who cares if you're already above 60FPS? We don't all play Crysis 24/7...