AMD's Quad FX: Technically Quad Core
by Anand Lal Shimpi on November 30, 2006 1:16 PM EST- Posted in
- CPUs
Final Words
AMD is going to have a very tough sell with Quad FX; although the CPUs are priced competitively, if the ASUS L1N64-SLI WS ends up just shy of the $400 mark it's a platform that is simply too expensive at no benefit to the end user. When only running one or two CPU intensive threads, Quad FX ends up being slower than an identically clocked dual core system, and when running more threads it's no faster than Intel's Core 2 Extreme QX6700. But it's more expensive than the alternatives and consumes as much power as both, combined.
There is the upgrade path argument, that eventually you will be able to put a total of eight cores in this Quad FX platform, but we can't help but wonder if the market for someone who wants a non-workstation 8-core setup for desktop use is a very small one. Although to AMD's credit we were able to create a scenario where even four cores won't cut it, making a case for the need for 8-core setups in the future. But the promise of eight cores in the future doesn't do a great job of justifying the Quad FX purchase today.
For those users who won't migrate to eight cores, once AMD's new micro-architecture debuts next year with native quad-core support, this expensive Quad FX platform will be notably slower than cheaper single socket systems. Quad FX is simply a very niche product, and in the era of power efficiency and performance per watt, AMD has released the proverbial SUV of high end desktops.
AMD hopes to sell more Quad FX processors than any FX processor in the past, which to us means that either AMD sees much more opportunity in this platform than we do, or that the previous FX processors simply didn't sell very well. Either way you slice it, there's only one AMD CPU we're really interested in and we won't get it until the middle of next year. Luckily for AMD, Intel doesn't appear to be doing anything huge between now and then either, so it looks like the CPU wars will cool down for a while after a heated few months.
Prepare to revisit this discussion in less than a year's time, and next time AMD will hopefully be much better prepared, armed with a new architecture and a cooler, smaller 65nm process. Until then, there's always Quad FX but you're better off with Kentsfield.
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Viditor - Thursday, November 30, 2006 - link
If they can...
The 680a chipset has a direct HT link to each MCP, the 680i obviously can't do that and must bridge through the SPP.
Now if only we could find a review that actually showed that...;)
Seriously, the one major benefit of Quad FX is that it can run 4 GPUs. While I appreciate all of the conjecture and speculation, it isn't really a test of the facts, is it?
defter - Friday, December 1, 2006 - link
<quote>Seriously, the one major benefit of Quad FX is that it can run 4 GPUs.</quote>How that's a benefit? You can have 8 GPUs in a same system (AMD or Intel based, it doesn't matter) with a couple of NVIDIA Quadro Plex 1000 Model II's if money isn't an issue:
http://www.nvidia.com/page/quadroplex_comparison_c...">http://www.nvidia.com/page/quadroplex_comparison_c...
JarredWalton - Friday, December 1, 2006 - link
Fact: Quad SLI (7950 GX2) works on 590 SLI and 680i.Fact: Quad SLI (8800 GTX) does not exist.
Until the second item changes, we only have the first to go on, which is that current quad SLI works - at least as much as it works anywhere - on both platforms. And the QSLI drivers are still largely broken - you can run benchmarks, but as soon as you start playing lots of games rather than just benching, problems crop up. Neverwinter Nights 2 for example doesn't even run properly with CrossFire or SLI, so let's not even worry about getting QSLI support for now.
JackPack - Thursday, November 30, 2006 - link
8800 GTX requies two slots, which means it won't fit in the 4x4 motherboard. Quad-SLI performance has already shown to be poor using two 7950 GX2 cards. Finally, how do you bridge four 8800 cards together?Viditor - Thursday, November 30, 2006 - link
Huh?
http://www.bit-tech.net/hardware/2006/11/08/nvidia...">Single slot 8800 GTX
This is only when using a single MCP, the 680a uses dual MCPs.
The 680i uses one MCP and one SPP.
By having 2 sets of bridges (one bridge per MCP).
JarredWalton - Friday, December 1, 2006 - link
Quad SLI has problems whether or not you have dual MCPs. It's driver and software related - basically the drivers don't do AFR on a lot of titles and so you end up with lower than 7900 GTX SLI performance.As for two slots, they're talking the width of the cards. They only plug into one slot, but they fill the adjacent slot. Quad 8800 GTX would require eight expansion slots right now. Given that Vista 8800 drivers aren't even out yet, I think NVIDIA has other things to do before they worry about moving beyond SLI'ed 8800 cards.
PrinceGaz - Thursday, November 30, 2006 - link
I suppose you could replace the HSF with something smaller which would fit in a single-slot, which would have to mean water-cooling.Quad-SLI performance (or lack of) is probably a driver-issue.
Don't 8800 cards have two SLI sockets therefore allowing you to chain together as many as you like (in theory)?
casket - Thursday, November 30, 2006 - link
It appears with win-xp sp2... this quad fx stinks. How about Win 2003 or Vista Ultimate? It might change things drastically.Neosis - Thursday, November 30, 2006 - link
I don't think the problems in the benchmarks are not an opperating system issue. Two processors having totally four cores are not the same as a processor having the same number of cores. Additional latencies will slow down the performance.Viditor - Thursday, November 30, 2006 - link
Actually, they probably are...Windows XP is not NUMA aware, while Vista is.
In this case there is no difference...the Kentsfield has exactly the same latency as a 2 socket dual core because the 2 dual cores on-board don't talk directly with each other.