Radeon X1900 XT Crossfire - Page 2

A Crossfire Chat

Howowowooow ... not so fast man .. hear me out: if you do decide to go the Crossfire path then please do so with the new X1000 series graphics cards. The x800/850 series' biggest limitation with regards to gaming is namely a maximum resolution of 1600x1200 at 60 Hz, and trust me when I say that in this year or the next, high-end gamers will all be moving towards 1920x1200 or higher resolutions with HD gaming around the corner and all kinds of new HD screens becoming available. The new X1000 generation allows exactly what ATI has in mind for Crossfire and has a far better chance in succeeding over the previous generations products. You can smack that rig up-to a 2560x1200 resolution which is great. Could somebody please sponsor us with a 30" Dell screen ?!

As you know, the new CrossFire X1000 series from top to bottom are Crossfire compatible. All cards and DVI connectors are able to handle Dual-Link DVI. Today we'll test on a lovely 24" LCD at resolutions up-to 1920x1200.

Yeah indeed... I need to clean up.

Let's walk through the installation

Now here's some good news. With upcoming Catalyst 6.5 drivers you'll be able to hook up similar Radeon X1000 series graphics cards up-to the X1800 GTO without the need for a master card AND you do not need the Y-Cable. Just plug these cards preferably onto a (2x) x16 PCI-Express lane mainboard and it should work. That's really good news.

High-end cards in Crossfire however do require a master and a slave card. The master card is a special board, whilst the slave is the usual Radeon that you can or have bought in the stores. Although you can mix among the cards I'd say for optimal performance please match the cards 100%

Example: You want to hook up a X1800 XL card in Crossfire - Well since there will be no X1800 XL Crossfire edition mastercard, so you will have to chip in 500 USD and make it work with the x1800 XT Crossfire edition card. Once you insert the CrossFire card into your system next to the Radeon X1800 XL, the CrossFire card will deactivate half of its 512MB memory in order to match up with the Radeon X1800 XL's RAM size. The Radeon X1800 XT CrossFire will maintain its higher GPU and memory clock speeds, though. However, investing in a 512 MB graphics card where only 256 MB will be used is a bit hard to swallow I think. I call this process dumbing down.

We see similar behavior today as we partner up an X1900 XT and x1900 XTX card. The XTX will be downclocked towards the XT speeds and you drop 75 USD in the trash bin. So if you decide to go high-end Crossfire simply buy the XT and the XT Crossfire edition cards. Let's have an overlook of the products available at this time and age.

The prices of course are manufacturer suggested retail prices and might even be cheaper in e-tail.

Radeon card	Pixel Shader Units	Vertex Shader Units	Texture Units	Max Threads	Core Frequency	Memory Frequency	Memory	Price in USD	Available
X1900 XTX	48	8	16	512	650	775	512 gDDR3	549	Now
ASUS EAX1900 Crossfire	48	8	16	512	625	725	512 gDDR3	549	Now
X1900 XT	48	8	16	512	625	725	512 gDDR3	499	Now
X1900 AIW	48	8	16	512	500	500	256 gDDR3	499	Now
X1800 XT	16	8	16	512	625	1.5 GHz	256/512 gDDR3	299/329	Now
X1800 XL	16	8	16	512	500	1.0 GHz	256 MB gDDR3	278	Now
X1600 XT	12	5	4	128	590	1.38 GHz	128 / 256 MB	149/199	Now
X1600 PRO	12	5	4	128	500	780 MHz	128 / 256 MB	99/129	Now
X1300 PRO	4	2	4	128	600	800 MHz	256 MB	99	Now
X1300	4	2	4	128	450	500 MHz	128 / 256 MB	79/ 89	Now
X1300 Hypermemory	4	2	4	128	450	1 GHz	32 / 128 MB	69	Now

You of course will also need a mainboard that can manage the two cards. ATI introduced a new variant of the Radeon XPRESS 3200 platform, one for AMD and one for Intel systems, based on the RD580 chipset. In the stores they'll be branded as the "Radeon XPRESS 3200 CrossFire Edition mainboard". Today we used the A8R32 MVP Deluxe from ASUS and despite how we initially had a malfunctioning board I must state that this mainboard managed to impress me. It is blazingly fast on all fronts and now also supports two 16 PCI-express lanes for dual graphics (16 lanes going to each), so you are immediately bringing massive bandwidth to the graphics ports, and the X1900 XTs will love that. Next to that you can find the ASUS A8R32 MVP mainboard under the 100 USD threshold which makes it an awesome buy.

We are going to review this mainboard separately from this review soon though, for now let us just focus on graphics performance.

Once you have your mainboard setup then it's time to connect both cards. NVIDIA does it with the SLI bridge and ATI decided to do it with that really impractical cable.

Why is that cable needed ? ATi uses it to composite images between the two cards.

ATI is producing a digital image from the DVI output of the slave card and then sends it to the large connector (DMS-59) on the master board. The master board will, on its terms, prepare its image and then send off both to a compositing engine that is processed on the master board. The master card is responsible for "fusion" of the images between the two boards and that can be done in a number of varieties. So that is why you need a primary card .. you have two cards rendering images and then there's is a compositing engine need which is located on the master card.

Okay .. back to the installation. On our latest RD580 based mainboard Crossfire review we had to place the master card in the lower PCI-Express graphics connector, which did not make sense to me. Naturally you'd assume that this will be the same with the successor .. ehheh. Nope. Good call, the master graphics card must be placed in the higher (closest to the CPU) PCI-Express graphics port.

After mainboard installation it was time for the Catalyst drivers. We took the latest Catalyst 6.3 Control Center Edition drivers and installed them. I tried to enable the Crossfire tag in the drivers and yes ..  I realized I made another mistake.

Here's the thing, when you look at the Crossfire y-cable you'll have a DVI connector leading from it. Your monitor must to be connected to that specific connector. My bad, I had the monitor connected towards the lower standard DVI port on the master card.

This photo shows the initial connection, the monitor was connected to the lower DVI connector. In this configuration you can't enable Crossfire mode in the Catalyst drivers.

We had issues (as explained in the article) we swapped the ASUS board with an RD480 MSI board to see if the cards where okay. Once ASUS fixed the mainboard issue we swapped back to that mainboard. Well, after I changed that BIOS we where able to enable Crossfire, and with one more reboot out of the way we were good to go and observe some raw gaming power.