Mobility HD3870 Crossfire - No compatible ATI drivers yet available?

Ok guys.. I know there's been some comparisons made between the GTXs in SLI, and the HD3870s in Crossfire.. And of course, we'd all like to know.. WHICH PERFORMS BETTER?! Well, here's something I've been thinking about and thought that maybe someone else out there could offer more insight.

The Mobility HD3870x2 is a single card, dual GPU platform w/ a 65nm technology. Also, this is the M76 Variant of the mobile ATI Card.
Just so you know Im not making this up: http://www.dvhardware.net/article17815.html

Now, the newer HD3870 for Crossfire is the 55nm, M88 as GPU-Z clearly also points out:



The problem here, is that you'll notice most if not all of us running the OCZ are using drivers that state we have the HD3870 x2. Fortunately, we DONT! The "x2" terminology doesn't represent Crossfire, but it does represent a single card with 2 GPUs on that same board. Well, we all know this isn't the OCZ setup. We have 2 individual cards, each with one GPU. Well, here's the catch..

Inside the .inf that installs the Video Drivers.. most of which you MUST mod with Mobility Modder..the modder adds 2 lines, forcing compatability.

"ATI MOBILITY RADEON HD 3870 X2" = ati2mtag_M76, PCI\VEN_1002&DEV_9509
"ATI Mobility Radeon HD 3870" = ati2mtag_M76, PCI\VEN_1002&DEV_9508&SUBSYS_02401043

The downside of this, is that it is installing and recognizing our cards as the 3870 x2 M76. There is no M88 in ANY .inf that is modded. And, I still haven't found the M88 in a non-modded .inf. ATI hasn't released any drivers for the card?! Is that the case? Im making an assumption by saying the driver install recognizes the cards as the 3870x2 because it's 2 GPUs with a smiliar config. But, as I said..these are NOT our cards.

Here's a Vendor ID list including ATIs:
http://forum.insanelymac.com/index.php?showtopic=134419&pid=952650&st=0&#entry952650

About 3/4 down the page you'll find the Dev Id 9509 - M88. However, if you scan through any of the Display Driver .infs released so far, you won't find a reference to M88 anywhere. It's configging out cards as the M76..kinda like configuring and force installing a 9800m GTX as a 8800m GTS. Well, obviously there's some differences! I may be way off base here, but I seriously doubt it. So, to all of you who keep making comparisons between the SLI vs. Crossfire.. wait until we actually have drivers that are MEANT for our computer. Otherwise, force install some 8800m drivers on your 9800m cards and then let's compare some benchmarks.

And, if anyone can enlighten the public to why this is..then please, be my guest. But it seems to me, that ATI is still slacking and isn't 100% supporting this setup yet. Which means..when our drivers do actually dome out, and they ARE compatible.. NVIDIA needs to hold onto their seats, cause the only thing stopping us right now are bad drivers.

 

Of course, that disappoints me even more about having pulled the trigger on the whitebook, as I'd thought that ATI was a little more on the ball than years before. This was my main concern with buying an ATI card as they've consistently proven their inability to write good, timely, graphics card drivers. I hope I didn't make a really big mistake...

 

It all depends on how ATI is actually implementing the mobile cards. They may very well be using 2 cards to do the same thing as on 1-X2 desktop card. The cable between the two cards could be acting just like the bridge built into the single card, therefore the drivers are true and correct. A sure fire way to find out is to see if both cards will operate the laptop independently as would work in a typical crossfire or sli setup. If they don't then what you have is an X2 split into two cards.

 

Are you suggesting that the two cards aren't identical, or that perhaps one card slot is the only one that can act as the primary/master?

 

Correct. The two cards are a master and a slave acting as a single Radeon 3870 X2 as opposed to 2 of the exact same cards as in a typical crossfire setup. That is why the laptop sees the card as an X2.

 

I see.

E-wrecked- I looked at the source information that you posted, but I didn't see anything about the 3870x2 being an m76. Instead, this is what I saw.

{“ ATI Mobility Radeon HD 3870 ,M88 ,9508“}
{“ ATI Mobility Radeon HD 3870 X2 ,M88, 9509“}

Did I misunderstand something, or just not look far/hard enough?

 

No no..you're correct. The cards are indeed M88s. However, the .inf(drivers) that are being released currently do not include any support for the M88 mobility series. The 4000 series is also supposed to be M88(from what I gather). However, looking at the OP you'll notice the M76 is the driver being loaded for the M88 cards in this rig.

 

Did alienware release a driver yet for these cards ? maybe they threw some cash at ATI for a custom driver for there machine

 

They released the 8.8 Driver, I believe... not a modded driver. I'll double check,

 

Yah, those are some OLD drivers. The 8.8 Catalyst drivers.. ATI releases an official driver once a month. Hence, the 8.11 this month. Next month will be 8.12, and then come january it will go to being catalyst v9.0 - The only good thing about them is that once a month there is an official release. On the downside, those are official Desktop drivers. It seems that the mobile version drivers are only released every quarter, from what I have seen. So, next month *should* be the mobility version, and if not..then hopefully January. But, with the release of the 4k series mobiles, then next month would make sense. And, that driver has some HUGE advantages for the 4k series. I'm hoping it also supports us lowly 3k mobility folks as well.

 

I'm pretty sure the Mobiliy 48xx is M98. This was shown briefly under the AMD/ATi Device ID page and the pictures of the Mobility 4850 at flickr.

As for mobility drivers, ATi is notorious for their lack of support with drivers for their mobile GPUs. They often delegate that task to the OEM/ODM of the notebook with the GPU. nVidia was much the same way a while back until they dominated the notebook GPU market, which is why most of their new WHQL drivers also include the 8600M, 8800M, 9800M, etc.

Hopefully things will change with ATi seeing that 1) the 4xxx series is successful and 2) notebooks outsold desktops last quarter.