If there is anything else you think should be added to the FAQ send me a PM (private message)

Q: I have a single 38x0X2 card and dont see a crossfire section in the CCC whats up with that?
A: You wont see one as its enabled by default so theres no section as theres nothing to change in that case.
2 X2 cards will obviously be able to disable Crossfire between the two cards but still wont disable single card Crossfire. There is one exception to this, the 4 port DVI 3870X2 cards can enable or disable Crossfire since otherwise the 2 extra DVI ports wouldn't work.

Q: I have enabled Crossfire in the CCC how can I check its working?
A: There are numerous ways with various games, one easy way is to use the pixel shader test in 3Dmark 2006 as performance is doubled with Crossfire enabled (or up roughly 50% if you add a single other card to an X2 card to make a trifire setup)

Q: I have a 38x0 card and a 2x00 card can I Crossfire them?
A: No you need to have two (or more) of the same family of cards ie a 2 lots of 38x0 cards or 2 (or more 2x00 cards.

Q: I have 2 matching 2x00 cards but they dont have a internal bridge connector so can I enable Crossfire?
A: Yes but it will be software Crossfire which is slightly slower than hardware Crossfire

Q: With CrossfireX enabled how many monitors can I use at the same time?
A: 2 currently.

Q; How come the video cards show up as 3800 series, and not HD3870's? Is this supposed to be this way? ( I have 2 sapphire HD3870's
A: Since theres no specific 4 stage ID in the INF file it will use the generic 2 stage ID, theres no loss in performance with this doesnt make any difference other than the title.

Q: Do the cards need an assigned IRQ?
A: No, although some people have issues with certain soundcards or network cards hogging an IRQ. Changing the slot the the network card or soundcard use fixes this. Check your motherboard manual for which slot uses which IRQ. Isnt an issue for most people.

Q: I have tried loads of different things but my performance is still low
A: Ensure your Motherboard Hypertransport speed is at 1000 or whatever speed your motherboard and chipset supports, some BIOS's default to 200 after updating them

Q: GPUZ shows that crossfire isnt enabled on my 3870X2 card
Q: GPUZ shows a low clockspeed on my 38x0 card
Q: GPUZ shows other info incorrectly
A: GPUZ is rather buggy

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Game.AMD Administrator

Edited: 06/25/2008 at 12:41 PM by spyre

Compatibility Chart Here:

http://ati.amd.com/technology/crossfire/charts.html

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[Antec Titan 650][Silencer 750W Quad (red)[MSI K9A Platinum (1.8)][AMD Athlon FX-62][Zalman CNPS9700led][OCZ 4GB DDR-2 800 Crossfire Edition][Visiontek HD4870 512MB][ATI TvWonder 650][Dual WD Raptor's 74GB][WD CaviarSE 250GB][Plextor PX-708A][Viewsonic VG2030WM][Logitech Keyboard & MX-518 Mouse][Vista Home Premium 32bit (SP1)][APC Smart-UPS 1500VA]

Many Crossfire or CrossfireX problems can occur if you do NOT have the proper power supply to feed your gear.

You should always check for a full list of Certified Power Supply here:

http://game.amd.com/us-en/cros...x_components.aspx?p=3

You can use this very neat PSU Calculator on this site to calculate how much power you really need.

http://extreme.outervision.com/psucalculatorlite.jsp

The eXtreme Power Supply Calculator contains 750+ CPUs including latest processors from Intel and AMD, latest graphics cards from NVIDIA and AMD (ATI) and more!




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[Antec Titan 650][Silencer 750W Quad (red)[MSI K9A Platinum (1.8)][AMD Athlon FX-62][Zalman CNPS9700led][OCZ 4GB DDR-2 800 Crossfire Edition][Visiontek HD4870 512MB][ATI TvWonder 650][Dual WD Raptor's 74GB][WD CaviarSE 250GB][Plextor PX-708A][Viewsonic VG2030WM][Logitech Keyboard & MX-518 Mouse][Vista Home Premium 32bit (SP1)][APC Smart-UPS 1500VA]

Edited: 03/17/2008 at 08:15 PM by Polar_FX

Q: How come CrossfireX is not working! I'm using Windows XP?
A: CrossfireX (Using more than 2 GPU's) is only available to Windows Vista with Catalyst 8.3 and above.

Q: Does CrossFire always improve performance ?
A: Not Always , there are some games that dont take advantage of CrossFire , so you wont see a difference between 2 cards and 1 card in those games , but in games that take advantage of CrossFire , 2 cards will perform better than one.

Q: My Crossfire 3Ddmark06 benchmark seems low.
A: The new HD series are really fast cards, way faster than the CPU. Some CPU are too slow to feed the video cards. A CPU bottleneck occurs. Pairing a very fast card with a slow CPU will definitly hinder the score. The only solution is to get a faster CPU or overclock your current one (At your own risk).

Q: Does CrossFire double the memory ?
A: NO, CrossFire does not double the memory , if You have a 512MB card , adding another 512mb card wont make your total memory 1GB, it still will be 512MB.

Q: My HD3870/X2 card only reports 512mb in CCC, It supposed to have 1GB of memory.
A: This is normal. X2 card is two 512mb cards with internal crossfire enabled. CCC will not report more than each card uses. See above

Q: What about the brand, clock speed and memory size ?
A: You can use diffrent brands, but always make sure to match the clock speed and memory size. It is true that if the clock speed do not match, the faster card will match the slower clocked speed card. For best performance, matching identical cards should be used.

Q: Do i have to get Crossfire memory ?
A: Some RAMs do have CrossFire logo's on them but there are many RAMs which dont have CrossFire logo's and you can use CrossFire with them without any problems.

Q: Some Motherboards support Crossfire at Dual 16x mode, some support it at Dual 8x mode and some support it at 16x 4x mode, what are the differences?
A: For getting the best results, you need a Motherboard that supports dual 16x mode. Dual 8X does hinder the performance slightly. On the other hand, you should avoid the 16X 4X this one is the weakest and doesn't perform very good.

Just felt like adding stuff to your FAQ. You can edit if need be Spyre.

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[Antec Titan 650][Silencer 750W Quad (red)[MSI K9A Platinum (1.8)][AMD Athlon FX-62][Zalman CNPS9700led][OCZ 4GB DDR-2 800 Crossfire Edition][Visiontek HD4870 512MB][ATI TvWonder 650][Dual WD Raptor's 74GB][WD CaviarSE 250GB][Plextor PX-708A][Viewsonic VG2030WM][Logitech Keyboard & MX-518 Mouse][Vista Home Premium 32bit (SP1)][APC Smart-UPS 1500VA]

Edited: 03/16/2008 at 07:49 PM by Polar_FX

Chipset PCI Express Mode

AMD 790FX 2 PCI Express 2.0 x 16 with 2 video cards
1 PCI Express 2.0 x 16 and 2 x 8 with 3 video cards
4 PCI Express 2.0 x 8 with 4 video cards

Intel X38 2 PCI Express 2.0 x 16, 1 PCI Express 1.0 x 4 *

AMD 790X 2 PCI Express 2.0 x 16

AMD 580X (ATI Xpress 3200) 2 PCI Express 1.0 x 16

AMD 570X 1 PCI Express 1.0 x 16, One PCI Express 1.0 x 8

Intel 975X 2 PCI Express 1.0 x 8, One PCI Express 1.0 x 4 *

AMD 480X (ATI Xpress 1600) 2 PCI Express 1.0 x 8
ATI Radeon Xpress 200 "CrossFire"

Intel P35, P965, 945P ** 1 PCI Express 1.0 x 16, One PCI Express 1.0 x 4

AMD 780G (Hybrid CFX ***) 1 PCI Express 2.0 x 16

* Not all motherboards based on Intel X38 and Intel 975X chipsets have three x16 slots.
** Not all motherboards based on these chipsets have two x16 slots, so CrossFire is only supported on models that carry two x16 PCI Express slots.
*** So far, only video cards based on Radeon HD 2400 and Radeon HD 3400 series are compatible with Hybrid CrossFireX. This technology only works under Windows Vista.

Thanks for Polar_FX for the info since it should be useful to people

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Game.AMD Administrator