Sign in with
Sign up | Sign in

The 990FX Chipset Arrives: AMD And SLI Rise Again

The 990FX Chipset Arrives: AMD And SLI Rise Again
By

AMD is laying the foundation for its Socket AM3+, Bulldozer-based Zambezi processors with the 990FX chipset, functionally identical to 890FX. The big news is that motherboard vendors are licensing SLI again, and we want to compare performance to Intel.

Generally, platform reviews accompany new processors. But in the case of AMD’s 990FX chipset, there’s both good and bad news.

The good news is that AMD still has a fantastic compatibility story. So, 990FX supports today’s Socket AM3 processors and the upcoming AM3+ CPUs based on the Bulldozer microarchitecture.

The bad news is that those Bulldozer-based chips are still not ready. Processors based on the B0 stepping are in the hands of motherboard manufacturers. But they’re all telling me that performance is nowhere near what they were expecting, and it’ll take another stepping to fix them.

Those 2011 sockets correspond to Zambezi, Llano, and the Brazos processors. Those 2011 sockets correspond to Zambezi, Llano, and the Brazos processors.

Technically, you could buy a 990FX-based motherboard today and drop in an existing Phenom II. But if you’re really lusting after a six-core Zambezi-based chip, it’d be better to simply wait a couple of months. Unless there was another reason to upgrade…

990FX: Same As 890FX, But Guaranteed Compatibility

The 990FX chipset employs the same silicon as 890FX. Didn't know today's launch was happening? Didn't know 990FX would be so similar to 890FX? If you were following me on Twitter, you would have! ;)

According to AMD, it’s incrementing the platform name to clarify compatibility with Bulldozer-based processors. When you see a board that centers on 990FX, the company wants you to know that its upcoming AM3+ CPUs are drop-in-compatible (again, 990FX-based boards will also take existing AM3 chips).

Why yes, I did Photoshop an 890FX block diagramWhy yes, I did Photoshop an 890FX block diagram

You need the 942-pin Socket AM3+ (AM3b) interface, though, in order to support Zambezi’s power and frequency management features.

Conversely, AM3+ processors also drop into Socket AM3 motherboards, given a BIOS update. Depending on the company that manufactured your AM3-enabled board, there may or may not be a firmware upgrade available immediately. So, understandably, AMD doesn’t want to leave the question of compatibility up in the air.

Update (4/29/2012): Much time has passed since AMD made the claim that AM3+-based processors would drop into Socket AM3-equipped motherboards. A few models with AM3 interfaces do support CPUs centering on AMD's Zambezi design, but most do not. If you own a platform with an AM3 interface, check before buying an FX processor. More than likely, you'll need a new motherboard with Socket AM3+.

Even with a new firmware, though, you won’t get those aforementioned features on an AM3 platform. Also, 890FX and 990FX both support HyperTransport 3.0 with transfer rates of up to 5.2 GT/s. According to MSI, 990FX adds HyperTransport 3.1 support with signaling up to 6.4 GT/s (apparently something we’ll see from the eight-core Zambezis).

I’m not a fan of rebadging, but in this case, it’s a necessary evil. Sure beats murdering a processor interface every time you introduce a new architecture (*cough* Intel). Most enthusiasts will probably want to upgrade anyway to match Zambezi and AM3+. But it’s nice to know that AMD has its eye on the backward and forward compatibility of its processors and platforms.

SLI: A Pleasant Surprise

More pertinent than any AM3+ discussion, at least today, is the addition of SLI support on 990FX boards. Frankly, there’s nothing stopping the motherboard guys from licensing SLI on 890FX as well, but nobody I’ve talked to has plans to do that. Instead, it looks like SLI will be used as a differentiator to get gamers stoked about upgrading their processor and motherboard when the FX-series (Zambezi) chips launch.

GeForce GTX 570 SLI on 990FXGeForce GTX 570 SLI on 990FXPhenom II X4 980 on 990FXPhenom II X4 980 on 990FX

As with Z68 Express, two-way SLI and CrossFire configurations are easily supported. AMD’s 990FX hits with 42 PCI Express lanes, giving each slot on a dual-card config its own 16-lane link (compared to Intel’s two x8 links). Don't get too worked up about this "advantage." Eight lanes is still enough for Intel's parts to compete aggressively. Don't believe me? Check out Thomas Soderstrom's three-part series on multi-card scaling.

Because 990FX boasts so much second-gen PCI Express connectivity, it doesn’t require NF200 to support three-way setups, though. Both of the 990FX boards that landed in our lab accommodate two- and three-way configurations (x16/x8/x8), along with quad-GPU arrangements using cards like GeForce GTX 590 and Radeon HD 6990.

GeForce GTX 570 SLI on Z68GeForce GTX 570 SLI on Z68Core i5-2400 on Z68Core i5-2400 on Z68

Without AM3+ processors to test, today’s 990FX launch only has one really interesting angle: SLI-based performance using a Phenom II X4 980 versus Intel’s Core i5-2400, both configurations armed with a pair of GeForce GTX 570 graphics cards. The comparison couldn’t get any more even. Our P8Z68-V Pro sells for the same $210 Asus plans to ask for the Sabertooth 990FX, and the Core i5-2400 sells for $5 more than AMD’s Phenom II X4 980. With all other components equal, this is a true head-to-head.

So, is the return of SLI support to AMD’s chipset family worth an upgrade? Let’s find out!

Ask a Category Expert

Create a new thread in the Reviews comments forum about this subject

Example: Notebook, Android, SSD hard drive

Display all 90 comments.
This thread is closed for comments
Top Comments
  • 24 Hide
    stingstang , May 30, 2011 1:44 PM
    Tom's, what the hell is this? "At the end of the day, it's the graphics cards which are the bottleneck."
    Did you go about benchmarking graphics cards, or was this a motherboard/cpu comparison? I'm tired of hearing this excuse all the time. We know you have a pair of 6990s and 590s in your shop. Get rid of that stupid bottleneck and DO IT RIGHT!
  • 19 Hide
    saint19 , May 30, 2011 2:03 PM
    I'd keep in mind that this performance review was made it with an AM3 CPU and not with the new generation.
Other Comments
  • -3 Hide
    Marco925 , May 30, 2011 1:19 PM
    But! Does it play metro 2033?


    It Does!!!!
  • 0 Hide
    Anonymous , May 30, 2011 1:23 PM
    nice to see support for both videocard producers. especialy for nvidia. now you can do amd+nvidia not only amd+ati(amd)
  • 0 Hide
    nforce4max , May 30, 2011 1:24 PM
    So fast that it sucks your eyeballs into the back of your skull C:
  • 24 Hide
    stingstang , May 30, 2011 1:44 PM
    Tom's, what the hell is this? "At the end of the day, it's the graphics cards which are the bottleneck."
    Did you go about benchmarking graphics cards, or was this a motherboard/cpu comparison? I'm tired of hearing this excuse all the time. We know you have a pair of 6990s and 590s in your shop. Get rid of that stupid bottleneck and DO IT RIGHT!
  • 19 Hide
    saint19 , May 30, 2011 2:03 PM
    I'd keep in mind that this performance review was made it with an AM3 CPU and not with the new generation.
  • 8 Hide
    geekapproved , May 30, 2011 2:19 PM
    What performance review? They didn't get to test anything. LOL
  • -4 Hide
    Yuka , May 30, 2011 2:30 PM
    Thanks for the review, but at lower resolutions we all know that the CPU differences will become clear. So you just proved that if a game is taxing on the GPUs, both solutions are equal and when the graphics card ain't being taxed, CPU differences become apparent... Ok, thanks for proving what we already know once more (not being sarcastic here >_
  • 7 Hide
    Anonymous , May 30, 2011 2:35 PM
    Useless test without Bulldozers. We already know Phenoms suck against SB. Hopefully Zambezi will be able to compete with SB in games, otherwise I'm ditching them, after 6 years of AMD CPUs in my rig.
  • 1 Hide
    Sud099 , May 30, 2011 2:55 PM
    We all know that SB CPU >> Phenom 2 series.Then how one can compare performance of two platforms while the Sb CPU performance is superior to Phenom2 series...
  • 6 Hide
    nukemaster , May 30, 2011 3:31 PM
    tommyschIs there any other brand?

    S3? :p 
  • 5 Hide
    amk09 , May 30, 2011 3:43 PM
    stingstangTom's, what the hell is this? "At the end of the day, it's the graphics cards which are the bottleneck." Did you go about benchmarking graphics cards, or was this a motherboard/cpu comparison? I'm tired of hearing this excuse all the time. We know you have a pair of 6990s and 590s in your shop. Get rid of that stupid bottleneck and DO IT RIGHT!


    I'm quite satisfied with this review. Nobody in their right mind is going to have dual 6990's or 590's and use a phenom II x4 or a i5 2400.

    Although the point you made is absolutely correct, it wouldn't be a very logical review.
  • 2 Hide
    Onus , May 30, 2011 3:57 PM
    Disappointing. I can clearly see the value of features like Virtu and SRT on the Z68 platform, but the 990FX doesn't offer anything comparable. Well, I've waited this long, another few weeks won't kill me to see if Fusion makes a difference...
    ...Except that July is the month I expect the parasites' efforts to destroy the value of the dollar will start coming to their fruition.
  • 3 Hide
    cangelini , May 30, 2011 4:18 PM
    stingstangTom's, what the hell is this? "At the end of the day, it's the graphics cards which are the bottleneck." Did you go about benchmarking graphics cards, or was this a motherboard/cpu comparison? I'm tired of hearing this excuse all the time. We know you have a pair of 6990s and 590s in your shop. Get rid of that stupid bottleneck and DO IT RIGHT!


    I don't consider that doing it right. Nobody in their right mind buys an AMD CPU for $180 bucks and then pairs it with two $700 graphics cards. GTX 570s is a realistic choice.
  • 1 Hide
    bit_user , May 30, 2011 5:38 PM
    Does it really use the same silicon as the 890FX? In that case, what took them so long?!? The whole point of backwards compatibility is lost if you launch on the eve of a new CPU release.

    I was actually just about to buy a 890FX board + Phenom II X4, last year, with plans to upgrade to bulldozer in late 2011. But then came the announcements of incompatibilities and the he-said/she-said rumors of possible compatibility and I just decided to play it safe and wait.

    Well, AMD lost my business, on this one. They could have at least sold me a Phenom X4. While I've been waiting, I've even been looking at the Sandy Bridge Xeons, which also support ECC and are more competitively-priced than previous generations.

    Nice going, guys.
  • 3 Hide
    wh3resmycar , May 30, 2011 5:45 PM
    i beg to differ. how can 2 gtx570s be a bottleneck in a real world situation? it's not like the world would suddenly turn upside down if they used a 580 instead.

    and no that's not what everybody wants at least with this 990fx "Preview".

    hopefully chris would do a follow up on this article once the dozers comes out.
  • -8 Hide
    Anonymous , May 30, 2011 6:23 PM
    This is wrong! It should be about 990FX not i5/980. I wanted to know how 990FXA does against 890FXA, not i5 vs Phenom II. That we already know. And why did you include only gaming benchmark? You were afraid that intel might look bad in multimedia benchmarks. Intel a**-kissers!
Display more comments