HD4870 + HD4850 in crossfire, anyone?

[solofly]

Thinking of offloading one of my HD4850s to a friend who has a HD4870. Anyone has a setup like that that can comment...?

 

[BTRY B 529th FA BN]

+1 id like to know too

 

[myocardia]

He will then have a 4850 CF setup, since the 4870 will be downclocked to the 4850's GPU & VRAM speeds. Of course, he could also overclock the 4850, to match the 4870.

 

[MarcVenice]

myocardia, I don't think that's the case. Do you have a link to that, or do you just assume it?

 

[SSChevy2001]

As myocardia said he'll have a 4850cf setup if he mixes the cards. The worst part is it will use slightly more power also.

http://www.hardwarecanucks.com...formance-review-8.html

 

[exar333]

Originally posted by: MarcVenice
myocardia, I don't think that's the case. Do you have a link to that, or do you just assume it?

I thought CF balanced the processing across the two cards, regardless if they were at two different speeds. I could be wrong (I don't have a link to substantiate this)

 

[footballrunner800]

I just tried it. 4870 + 4850 both visiontek. Whenever im playing a game the computer just shuts down. No BSOD just shuts down. It looks like a PSU issue but im only measuring 520w on a 750w corsair psu. Cats 8.10 make crysis warhead performance much better. I was getting 35-40fps on the first level.

 

[footballrunner800]

after changing the pci-e power plug, it seems that everything is working well.
Here are some 4850+4870benchamrks (i will update it later)

4870 855/1100
4850 700/1050
Catalyst 8.10rc2

Company of heroes
1680x1050 DX10 16xAA Very High
AVG 58.5
MAX 61.7
MIN 39.3

Crysis Warhead
1680X1050 DX 10 NO AA ALL Enthusiast
AVG 35.48
MAX 45.48
MIN 20.97

 

[MarcVenice]

Originally posted by: ExarKun333

Originally posted by: MarcVenice
myocardia, I don't think that's the case. Do you have a link to that, or do you just assume it?

I thought CF balanced the processing across the two cards, regardless if they were at two different speeds. I could be wrong (I don't have a link to substantiate this)

I thought so too, but the benchmarks show no difference between a HD4870/HD4850 setup and a HD4850/HD4850 setup. So since they perform equal the HD4870 must clock down ...

 

[emtownsend]

I've got a 4850 and an X48 board and would like to Crossfire as well. I believe the differing GPU issue was resolved with CrossfireX right? Hum... Have to pop over to ATI to check it out...

 

[emtownsend]

Here is a recommended combination chart from ATI:
http://game.amd.com/us-en/cont...combo_chart_July08.jpg

 

[BTRY B 529th FA BN]

I thought the 3870 and 3850 did better than 2 3850's in CF

 

[Tempered81]

Originally posted by: footballrunner800
after changing the pci-e power plug, it seems that everything is working well.
Here are some 4850+4870benchamrks (i will update it later)

4870 855/1100
4850 700/1050
Catalyst 8.10rc2

Company of heroes
1680x1050 DX10 16xAA Very High
AVG 58.5
MAX 61.7
MIN 39.3

Crysis Warhead
1680X1050 DX 10 NO AA ALL Enthusiast
AVG 35.48
MAX 45.48
MIN 20.97

could you run those two benches on a single 4870 or single 4850 so we can get an idea of what kind of impact CFX is making? Then we can compare it to benches of 4850 CFX. Thanks!

 

[footballrunner800]

Radeon 4870 830/1100

Crysis Warhead DX10 ALL Enthusiast
AVG 24.95
MAX 29.96
Min 17.54

Ill post some more over the weekend cause im busy atm

 

[solofly]

So it works... Thanks guys!

 

[apoppin]

Originally posted by: solofly
So it works... Thanks guys!

Of course it works

but how much faster is it than 2 x 4850?

i just sold my 512MB 4870 because it IS holding back my 4870x2.

How much it is holding it back over the 1GB version i do not know

yet

i just ordered this ... $269 after $20 MiR

http://www.newegg.com/Product/...x?Item=N82E16814121277

ASUS HD4870 1GB

i guess will find out "how much"
- but i am getting a good idea about how cutting the 1GB down to 512MB would affect a 4870x2 if it shipped that way; and i will know a LOT more about X3 CF when i RErun all my benches with "matched" CF .. 1GB 4870 + 2GB X2

i will keep you updated

 

[cusideabelincoln]

So, apoppin, does that mean I am going to have wait longer for your benchmark results? I am really interested in how a single HD4850, 4870, and/or 4870X2 perform on different platforms (pci-e 1.1 vs. 2.0).

 

[Cookie Monster]

Its always been the case where the faster card will try to synchronize with the slower card by downclocking (there could be other methods but not certain). This was one of the main reasons why nVIDIA never had this for SLI. It didn't make any sense, since the faster card will always be dragged down by the slower one.

 

[apoppin]

Originally posted by: cusideabelincoln
So, apoppin, does that mean I am going to have wait longer for your benchmark results? I am really interested in how a single HD4850, 4870, and/or 4870X2 perform on different platforms (pci-e 1.1 vs. 2.0).

Not very much longer .. i am almost done with X2 .. just a few more benches to run tonight; a couple of hours at most with X2

Here are preliminary conclusions:

First of all there is Zero practical difference with a single HD4870 on a 1.0 PCIE MB vs. on a 2.0 MB
[all of those benches are done]

So FAR .. with the X2, it looks like a 1 or 2% difference at most having 2x the bandwidth of PCIE 2.0 over 1.0

With X3, tonight, i will begin to explore my X48's MB's performance delta increase with 16x+16x PCIe over CF in 16x+4x [those are completely done on P35 MB; just waiting to compare with X48's results tonight]

THEN i publish my results ... probably Sat all the rough figures will be organized and put into graphs .. On Sunday, i expect to write the review
On Monday i send off my 512MB version of 4870 and put in my 1GB version into CF and i will also explore single card results between 512MB and 1GB 4870

so it is ongoing testing; till the new cards .. but i AM almost done with what you asked for

it turned out to be [much] more ambitious that i originally planned - i expanded it - with lots of retesting.

Anyone looking for the 4870-1GB version:

http://www.newegg.com/Product/...x?Item=N82E16814121277

$269 after $20 MiR - WoW trial included

good deal!

 

[Zebo]

Nice to know - reminds me a bit of AGP to PCIe Of course today I doubt you could build these cards on AGP and be competitive...

1-2% well within the margin of error. Do you do 3 runs of each or just one?


Anyway thanks look forward to your review

 

[apoppin]

Originally posted by: Zebo
Nice to know - reminds me a bit of AGP to PCIe Of course today I doubt you could build these cards on AGP and be competitive...

1-2% well within the margin of error. Do you do 3 runs of each or just one?


Anyway thanks look forward to your review

thank-you!

and that's what i am thinking [so far, i haven't got to Crysis yet] .. i do 3-5 runs of each bench .. they got to agree with each other

i think done by Sunday .. barring unforeseen ..

 

[Tempered81]

Originally posted by: footballrunner800


Catalyst 8.10rc2

Radeon 4870 830/1100
Crysis Warhead 1680X1050 DX10 ALL Enthusiast
AVG 24.95
MAX 29.96
Min 17.54


Here are some 4850+4870benchamrks (i will update it later)

4870 855/1100
4850 700/1050
Crysis Warhead
1680X1050 DX 10 NO AA ALL Enthusiast
AVG 35.48
MAX 45.48
MIN 20.97

http://images.hardwarecanucks....ames/CWH/GPUCharts.jpg

Originally posted by: apoppin

Originally posted by: solofly
So it works... Thanks guys!

Of course it works
but how much faster is it than 2 x 4850?

About on par with HD4850 Crossfire.
4870 + 4850 VS. 4850 CF review:
http://images.hardwarecanucks....SFIRE/CROSSFIRE-30.JPG

Interesting Crysis warhead review here comparing performance with Enthusiast vs. gamer, DX10 vs. DX9, dual vs. quad core, 4870x2 vs. gtx280, xp vs. vista, 2GB ram vs. 4GB ram, etc:
http://www.hardwarecanucks.com...erformance-review.html

The only thing it's missing is Crossfire & SLi.

Originally posted by: myocardia
He will then have a 4850 CF setup, since the 4870 will be downclocked to the 4850's GPU & VRAM speeds. Of course, he could also overclock the 4850, to match the 4870.

:thumbsup:

 

[solofly]

Originally posted by: apoppin

Originally posted by: solofly
So it works... Thanks guys!

Of course it works

but how much faster is it than 2 x 4850?

i just sold my 512MB 4870 because it IS holding back my 4870x2.

How much it is holding it back over the 1GB version i do not know

yet

i just ordered this ... $269 after $20 MiR

http://www.newegg.com/Product/...x?Item=N82E16814121277

ASUS HD4870 1GB

i guess will find out "how much"
- but i am getting a good idea about how cutting the 1GB down to 512MB would affect a 4870x2 if it shipped that way; and i will know a LOT more about X3 CF when i RErun all my benches with "matched" CF .. 1GB 4870 + 2GB X2

i will keep you updated

I'll be doing something similar to what you're doing but with HD4850s. Right now I've got three HD4850s w/512mb. My next purchase will be HD4850X2 followed by one more HD4850 w/1GB of memory.

First I'll try... 2xHD4850_512MB + HD4850X2 2GB (for quad gpu) and than like you HD4850_1GB + HD4850X2 (fro tri...)

All this will be done mid-November when get my hands on an ASUS P6T Deluxe mobo powered by X58 chipset baby (16x 16x 8x) and I'll be in heaven...

 

[apoppin]

Originally posted by: solofly

Originally posted by: apoppin

Originally posted by: solofly
So it works... Thanks guys!

Of course it works

but how much faster is it than 2 x 4850?

i just sold my 512MB 4870 because it IS holding back my 4870x2.

How much it is holding it back over the 1GB version i do not know

yet

i just ordered this ... $269 after $20 MiR

http://www.newegg.com/Product/...x?Item=N82E16814121277

ASUS HD4870 1GB

i guess will find out "how much"
- but i am getting a good idea about how cutting the 1GB down to 512MB would affect a 4870x2 if it shipped that way; and i will know a LOT more about X3 CF when i RErun all my benches with "matched" CF .. 1GB 4870 + 2GB X2

i will keep you updated

I'll be doing something similar to what you're doing but with HD4850s. Right now I've got three HD4850s w/512mb. My next purchase will be HD4850X2 followed by one more HD4850 w/1GB of memory.

First I'll try... 2xHD4850_512MB + HD4850X2 2GB (for quad gpu) and than like you HD4850_1GB + HD4850X2 (fro tri...)

All this will be done mid-November when get my hands on an ASUS P6T Deluxe mobo powered by X58 chipset baby (16x 16x 8x) and I'll be in heaven...

That is really cool! i just could not wait for x58 and i really believe an O/C'd Penryn will hold its own in gaming against i7 till Spring when i will follow you on the MB upgrade. Especially considering my e8600@4Ghz is at stock VCORE and the core temps are up only 3C over it's stock 3.33Ghz. i can't wait to really O/C her when i flash this MB to Rampage BIOS next week. Keeping my PC cool will be the problem.

These off-the-wall crossfire combinations appealed to the "cheap" in me when i first went for "frankenfire" starting with my 2900p/xt .. and it was really close to xt CF performance with the pro OC'd.
.. at any rate, i love it; plus upgrading the GPUs is really not that expensive if you don't wait too long to resell them. It is pretty important also, i think, to be able to explore the effects of varying the amount of VRAM available to the GPUs, shared or otherwise; there is absolutely nothing like getting your own hands on a few cards and going for "mix and match" .. just for the pure exploration. i don't think you can do this very cheaply with SLi; they are missing out

As soon as i log off, i put in my 512MB card in together with the X2 for the final time they will be [mis]matched in CF-x3. After i rerun all my benches again [now on x48 MB to compare with p35's limited CF], i will put in 4870/1GB on Tuesday and run them all over again . . . and then all over again with the new cats ... which will hopefully improve X3-CF even further. i personally believe that this is something AMD *must* do to stay ahead of Nvidia; i am one that still thinks Nvidia has a little "surprise" coming with the 55nm shrink for the ones that think it is 'just a shrink'.

.. and don't worry .. i am again finding time to play PC games also - there is more to gaming life than just running benchmarks; you have to be pragmatic and actually play the games to get a real "feel" for how the cards really perform. That is largely what led me to access 512MB vram as insufficient for playing at 19x12 to my liking.

 

[rickyman123]

i want to know if i can crossfire the 3450 and 4550 or not.