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Is 'Radeon Crossfire' Possible on Studio XPS 9100? Via an 'X8 to X16' Adapter?
Greetings All,
Recently bought a Dell Studio XPS 9100, featuring a Dell-manufactured Motherboard (Model: 05DN3X version A00, Intel X58 Chipset, i7 930<-->980X, HD5670<-->HD5970) and unfortunately: exactly one PCIe x16 slot.
There is an open x8 slot, however, and I've been told that any full-size x16 card will fit into an x8 slot using X8 to X16 adapter PEXP16-SX-16/8. (I'm thinking of crossfiring two HD 6870's off of a Booster X5 supplementary PSU.) (Not sure if there are other/better Adapter makes/models out there.)
On the other hand, at least one PEXP16-SX-16/8 seller is offering the following caveat: "Please note that this lane converter may not be compatible with some higher end video cards and workstation cards."
1. Will the mid/high-range Radeon HD 6870 be compatible with this X8 to X16 Adapter? Perhaps this is a question only a direct test can answer, or maybe the manufacturer. Space inside the case should not be an issue, though.
2. Assuming that the Adapter will work with the HD6870, is it still possible that this Dell motherboard (05DN3X version A00) will fail to support ATI Crossfire? The motherboard of the 9100 is based on the Intel X58 chipset ("...this chipset delivers dual x16 or quad x8 PCI Express 2.0 graphics card support..."), but are there certain additional features required for ATI Crossfire support, and are they possibly lacking in this Dell-manufactured, Dell-specific X58-based Motherboard?
3. What may perhaps be telling is the fact that on the specs page, the x16 slot is explicitly described as a 'Graphics' slot, while the x8 slot has no such label. "PCIe x8: 1 slot. PCIe x16 (Graphics): 1 slot."
4. Note to Dell: The answers to these questions are very hard for users to determine, given the sparse documentation for this system and many others on your site (the online Service Manual for the 9100 is short on specifics, as is the order page). Since you're using proprietary technology, it is important to inform the consumer about potential compatibility issues, or at the very least provide exact specifications: if not on the order page, then at least in a more remote location on the site. It should be easier to find answers of this kind, and one should be able to consult a document (rather than calling a representative or writing a long post) that is more or less comprehensive, in order to make purchase decisions, or when planning upgrades, or indeed whenever issues of this kind may come up.
5. An internet search shows that this particular issue has come up at least once before, on a Japanese forum, which Chrome kindly translated for me. Possibility of using an Adapter was not mentioned in that thread, however.
Thanks for your help!
Masi_GC
268 Posts
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November 10th, 2010 12:00
Hi Schopenhauerian,
I would recommend that you bide your time and wait for the prices to plummet on a HD5870 or better still, a HD5970. This is almost sure to occur after the release of the HD6900 series card (which is expected ~the end of November).
Although the Intel X58 chipset is capable of supporting Crossfire, it is not at all certain that the Dell custom BIOS will. Also, there is good reason to expect these cards will not work with the PCEe X8 to X16 adapter. PCI and PCIe buses require that the signal path be a specific length. Sometimes, you see in the board design that some traces take a serpentine path in order to meet this requirement. The adapter mentioned in the post would increase the length of the signal path resulting in corruption of the signal.
And even none of the above was an issue, how would you secure your card in the machine? The bracket would be 1.05" above the rail. Even if you made a custom spacer and used long screws, the bottom of your large, heavy dual slot card would not be properly secured.
Masi_GC
Schopenhauerian
6 Posts
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November 13th, 2010 23:00
Greetings Masi_GC,
Thanks for the feedback! Clearly, on a system like this, it would be much more sensible to wait for the 5970 price drop, or to get one of the 6900 models, rather than purchasing two 6870's and attempt a Crossfire setup. Since at the time of posting I already had one 6870 in hand, I will just have to be content with this card as it is. :)
I appreciate your assessment of the Adapter I cited in that link. There is another Adapter out there (0.8" above the rail), but the merchant claims that it will only work with Video Cards that use GDDR3 or lower (no GDDR5 Cards) and moreover, claims that this is a limitation of the Motherboard, rather than the Adapter (note: the merchant did not know my system specs). The latter claim seemed questionable at the time, but perhaps was his way of suggesting that the signal corruption you describe would be inevitable in any such Adapter?
Space could be an issue in an Adapter setup, though there would be a good 1.25" between the card and any obstacle, and an easy modification would make it 2.25", while the adapter would add only 0.8-1.05" (but then again, the 6-pin PCIe connectors, on the very same side, would take up some of that space). Finding a way to support the card inside the case wouldn't be too hard, but clearly there are a whole host of other issues that would be a challenge, and then some (an Adapter than supports GDDR5 being perhaps out of the question).