ATI HD4870X2 Owners Thread - Overclock.net

**Robilar** · 08-13-08

New owners please post your cards and results.

This is one big card. It's physical length is 10.5".

Also the Sapphire card came with a full registered version of Vantage.

My Asus card comes with Asus Smart Doctor, a proprietary monitoring and overclocking software for the card (and a 3 year warranty).

My initial test results comparing a pair of Sapphire HD4870's and the Sapphire HD4870X2 is that benches and game tests (GRID and COD4 specifically) show virtually identical scores at 1860x1050 with all settings maxed out. Given that this board has double the ram and that there are reviews on the web that show performance increases at higher resolutions, Once I get a bigger monitor I will test as well.

Just released:

There is a new tool which allows for fan speed control on the 4870 X2, its called Experttool-ATI

http://en.expreview.com/img/software...ertool-ati.exe

Note: ATI has informed me (as a result of my inquiry); You cannot Crossfire an HD4870 with an HD4870X2! (see attached jpeg)

However, Grunion here on OCN has gotten an HD4870 and a HD4870X2 to work together in Tri-Fire (requires Vista).

Hardware Canucks has discovered that there is potentially a compatibility issue between DFI X38/X48 boards and the HD4870X2

http://www.hardwarecanucks.com/forum...review-22.html

DFI Motherboard Owners….Take Note

"Unfortunately it has come to our attention that the fix listed below is not working for some people while others have claimed it worked. Thus, until we have either heard from DFI regarding this issue or the community is given a fix we are recommending you AVOID DFI X38 and X48 motherboards if you intend to buy this card.

You may not believe it but we had much, much more planned for this review but unfortunately our DFI motherboard conspired to haunt us again and again. Other than the fact that our LanParty DK X38 T2R decided to mysteriously give up on our very slight memory overclock, it refused to cooperate when we installed the HD4870 X2 into it. An ASUS X48 P5E Deluxe worked without a hitch, as did a Gigabyte EP35 and ASUS P5Q Pro so we knew it wasn’t the chipset and had read of these same things happening to owners of the HD3870 X2 when pairing that card up with certain DFI boards.

Basically, what happened was that we installed it into the board and a BIOS splash screen would not display even though the LED indicators told us everything was booting fine. There just wasn’t any video signal coming through the card so we somehow deduced that there was an issue with the X2’s display output. Well, we popped in the second HD4870 X2 card and lo and behold, had the same issue. Somewhere within the ensuing flurry of BIOS flashes, the motherboard decided enough was enough and finally died leaving us without a board and an approaching deadline.

To cut a long story short, we brought in another DK X38 T2R along with a beastly LanParty LT X48 T2R and found both new boards to have the same video display issue so we immediately knew that it was the board itself and not the card. After searching through the DFI Beta site, a BIOS was found that completely resolved the problem with the incompatibility between the motherboard and the HD4870 X2.

At this time we have only experienced problems with DFI’s X48 and X38 boards. The P35 and P45 series seem to be fine but if you are having problems with either of these chipsets, please post in our HD4870 X2 comment thread and we will try to sort things out.

Below we have listed the motherboards which may be affected by this problem as well as links to their corresponding Beta BIOS pages. You should use the most recent BIOS file we indicate or the latest one available.

LANPARTY DK X38-T2R: X38D725

LANPARTY DK X38-T2RB: X38D7251

LANPARTY DK X48-T2RS: X48DD725

LANPARTY LT X38-T2R: X38AD725

LANPARTY LT X48-T2R: X48AD725

LANPARTY LT X48-T3RS: X48GD725

LANPARTY UT X48-T2R: X48CD725

LANPARTY UT X48-T3RS: X48BD725

If your motherboard is not listed here, please visit the main page to the DFI beta BIOS site and look for your motherboard in the drop-down menu.

Use beta BIOS at your own risk..they are Betas for a reason folks.

The main problem we can see with this is that if you are building a new computer and do not have access to another graphics card, you will be in a fair bit of trouble. This is because you will have no way to update the BIOS if you can’t get a video signal. So, we recommend that if you are planning on buying a DFI board and the HD4870 X2 that you buy a cheap PCI-E graphics card just in case you have the display problem that seems to pop up on these boards. On the other hand, if you are upgrading to the HD4870 X2, you should update your BIOS before installing your new card."

[Credit to Ghostleader for finding and posting this article]

Again thanks to Grunion, he has been able to get the card working on his DFI X48 board with a new bios release. He has indicated that there are some signal issues though

Sideport and Bridge Chips

The Radeon HD 3870 X2’s bridge chip was limited to PCI-Express 1.1, meaning data transfer rates between each GPU—and the PCI-Express x16 interconnect—was limited to just 2.5GB/sec via the bridge chip and a further 0.9GB/sec via the CrossFire interface. This means that the maximum interconnect bandwidth on the Radeon HD 3870 X2 is 6.8GB/sec.

AMD created sideport on the 4870X2 series due to their belief that a lack of bandwidth contributed to some of the performance problems with the 3870X2 series.

With RV670, you could say that the 3870 X2 was a bit of an afterthought (from a design perspective), but with RV770, the 4870 X2 was a big part of the design process right from the start. With that in mind, AMD felt there was a need for more bandwidth and so invented an additional interconnect path between the two GPUs. AMD calls this technology Sideport and it’s basically a direct 5GB/sec (bidirectional) highway that bypasses the PCI-Express 2.0 bridge chip. In many ways, it’s similar to PCI-Express technology but because it’s only designed as a communication path between two AMD/ATI GPUs, the design is a lot more streamlined. What’s interesting though is that we’re unable to see whether Sideport makes a great deal of difference because AMD has chosen not to enable the technology in the drivers at this time.

One area where changes have been made is in the PCI-Express switch. AMD indicates that it has worked with PLX to make some refinements to this bridge chip to further improve performance in scenarios where bandwidth (and/or scaling) is an issue.

The biggest change, aside from the interface speed double up is the introduction of a broadcast write function. This essentially allows the bridge chip to conserve bandwidth by ‘broadcasting’ data to both of the card’s GPUs simultaneously. This could definitely improve performance in these scenarios.

We are still at the mercy of driver profiles however.

ATI Crossfire Extension Software App:

"ATI CrossFire Xtension may become your favourite application after the next sentence. Just released with the pilot version 1.0, ATI CrossFire Xtension is a cool utility that allows you to create custom profiles and force CrossFire support on non-supported or new games and applications, both for Direct3D and OpenGL."

http://www.geeks3d.com/wp-content/pl...load.php?id=33