Hey, I currently have an hd 4850 x2 the 2gb version. Now I am looking to get another GPU I wanted the 4870x2 card. Now if I crossfire the 2 cards and have 4 GPU's will it work well. Now the 4870x2 and the 4850x2 I believe have the same RV770 cores, the 4870x2 just runs faster. Now the memory is different, the 4850x2 is GDDR3 and the 4870x2 is GDDR5. Now if running 2gb of each will 2gb of the DDR5 run at DDR5 speed and the DDR3 run at DDR3 speed, or will all 4gb run at DDR3 speed, since that is the lowest speed. Also is it okay to corssfire these two cards. I really want a 4870x2, so I might crossfire the 2 until I can sell the 4850x2, but in the mean time I will be cross firing them.

Besides slowing the 4870 x2 down, many games do not scale well (or at all) past 2 GPUs. The 4850 X2 is not a particularly powerful card and is really held back by DDR3 (why Sapphire did not use DDR4 I will never know), and although it is faster in most cases than a single 4870, the 4870 x2 is much better.

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ASUS Crosshair Formula III
Phenom II X3 720BE @ ~3.43ghz
HT Link & CPU/NB Frequency @ ~2500mhz
8GiB OCZ Platinum DDR3 1600 @ 1664 7-7-7-16 1T 43.5ns avg latency
Sapphire Radeon HD 5970 OC 800/1150 (stock voltage)
SeaSonic M12 SS-700HM
Vista x64 SP2

hi man, hey i want to know if i can run two 4890 in crossfire with a power supply corsair tx750w, i have mobo 790gx, 4 gb ram ddr3 1333, cpu 955 3.2gzh, and two HDD. i want to buy two cards in cross fire i wanna two 4890 but i need know if my power suppy can run them in crossfire. tanks man

Heya,..

 

You know, in the time it took you to spam two people's unrelated threads with the same question, you could have found the answer on the CrossFireX pages ..

 

GG

Furthermore, if you do purchase the 4870x2, it will only run as fast as the 4850x2....you're wasting money.  If you truely need a qudfire rig, then get another 4850x2.

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Upgraded FX6800-01e; X58 MoBo; i7 920 stock; Corsair 8 GB DDR3 RAM 1066MHZ (8-8-8-19); Seagate 750 GB HD SATA II; 700W PSU: Sapphire (XFX BIOS) / XFX 1 GB 4850s @700/1200 - Crossfire; 1 - 120mm exhaust & 1 - 120mm cool air fan and 2 - 80mm cool air fan; Samsung SyncMaster  25.5" 1900X1200 native display and Dell-E207WFP 22" 1680X1050 native display; Windows Vista Premium SP 2 64 bit; Logitech wireless keyboard / laser mouse.

woh, didn't see that this thread was started in March 2009.  My bad.  I guess the noob spamed the thread and put it back up on the first page.

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Upgraded FX6800-01e; X58 MoBo; i7 920 stock; Corsair 8 GB DDR3 RAM 1066MHZ (8-8-8-19); Seagate 750 GB HD SATA II; 700W PSU: Sapphire (XFX BIOS) / XFX 1 GB 4850s @700/1200 - Crossfire; 1 - 120mm exhaust & 1 - 120mm cool air fan and 2 - 80mm cool air fan; Samsung SyncMaster  25.5" 1900X1200 native display and Dell-E207WFP 22" 1680X1050 native display; Windows Vista Premium SP 2 64 bit; Logitech wireless keyboard / laser mouse.