Socket-AM2+, Not So Positive?

When AMD first started talking about Phenom it boasted backwards compatibility with current Socket-AM2 motherboards, as well as a new Socket-AM2+ platform that would enable higher performance and better power management.

We are currently looking into Socket-AM2 motherboard compatibility, but not all vendors have Phenom-ready code for their motherboards as of today. While Phenom should work in virtually all Socket-AM2 motherboards, it's tough to say which will work by the time you can actually buy these things.


AMD's Spider platform, well, minus the graphics card - the 8800 GTX is still our testbed GPU of choice.

Socket-AM2+ motherboards, most of which are based on AMD's new 790FX chipset, were supposed to bring a tangible performance increase when paired with a Phenom processor. Phenom's L3 cache and North Bridge work on the same power plane, one separate from the rest of the CPU. Socket-AM2+ enables the use of two separate voltages, one for the L3 cache/NB and one for the rest of the CPU, whereas Socket-AM2 motherboards run the entire chip at the same voltage. The original plan was for Socket-AM2+ motherboards to run the L3 cache/NB at a higher frequency than the rest of the chip, unfortunately it looks like AMD wasn't able to make that happen.


Socket-AM2+ in action

Currently, the L3 cache/NB on these chips runs at a fixed frequency that's actually lower than the rest of the CPU frequency: 2.0GHz. We tested Phenoms running from 2.2GHz all the way up to 2.6GHz, and in all cases the L3 cache and North Bridge ran at 2.0GHz. We're not sure if this will ever get fixed, but it's somewhat disappointing as it was supposed to be a major reason for upgrading to Socket-AM2+ (but it's good news for current AM2 owners).

Right now it looks like the only benefit to Socket-AM2+ is support for DDR2-1066, which we've been having problems with internally already. If you've got a good Socket-AM2 motherboard, you may not need to upgrade to get the most out of Phenom.

First Tunisia, then Tahoe? Overclocking
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  • eye smite - Tuesday, November 20, 2007 - link

    Who cares what this goofball said in his review, or all you other haters. AMD is following their roadmap as they've laid it out, they released early samples cause of the noisy minority screaming for a new chip and it didn't turn out right. You think actual production chips will have these issues or not mature over the next few weeks? Good God there's alot of you people out there with unrealistic expectations and some severe perception issues. If you can't say anything worthwhile about the phenom launch, why don't you just quit typing and spare some of us that look forward to seeing this chip actually release and mature and give us a quad core that isn't the intel p3 based quad core.
  • feelingshorter - Monday, November 19, 2007 - link

    Thats how all AMD fans feels. I was hoping at the VERY least that AMD cpus would have a lower idle/max power usage. That would of been a sell point even if Intel CPUs are faster. Too bad AMD's processors are lacking all across the board. But as a college student, if they price it REALLY cheap, i'd be willing to stick with AMD.
  • Regs - Monday, November 19, 2007 - link

    I was hoping they would of offered 2.4 GHz at around 200 dollars. This...this...is just horrible. Now I have no excuses left to not upgrade to a Intel Q.
  • elfy6x - Monday, November 19, 2007 - link

    This was a very sobering article. On a slightly brighter note, Toms Hardware was able to get their Phenom to 3.0Ghz stable using air cooling, so perhaps there is some hope just yet. The nice thing is that AM2 motherboards can use this processor so the upgrade ability is theoretically friendlier than some of Intel's boards. As long as AMD prices it accordingly, I think it will do alright. It will be nice when AMD really gets going *someday* and we have another successor with a similar bang that the K8 had at its introduction.
  • erwos - Monday, November 19, 2007 - link

    Hint: the samples they send to reviewers tend to be hand-picked for overclocking. The fact that Tom got a good OC out of it probably means nothing.
  • DrMrLordX - Monday, November 19, 2007 - link

    Tom got the same overclock Anand did. Anand ran a comprehensive suite of stability tests which forced him to step the overclock back to 2.6ghz for stability. Tom ran 3dMark06 once and did not/could not/was not allowed to test for stability.

    This is what happens when you drink the Kool-Aid. And yes, I'm looking at you Tom's Hardware.
  • calyth - Tuesday, November 20, 2007 - link

    "This is what happens when you drink the Kool-Aid. And yes, I'm looking at you Tom's Hardware."

    Really. What's this Intel Resource Center doing on Anandtech?

    IMO it's nothing terribly wrong that review sites getting a bit cosier with manufacturers. Stuff don't comes free. I still read Toms and I still read Anandtech, but I try to make up my own mind.
  • retrospooty - Monday, November 19, 2007 - link

    "This is what happens when you drink the Kool-Aid. And yes, I'm looking at you Tom's Hardware."

    Funny, a decade later and still nothings changed. I stopped soiling my browser with Tom's 10 years ago. LOL
  • flyck - Monday, November 19, 2007 - link

    the bug that forced amd to withdraw the higher clocked phenoms is present when the cpu is clocked higher. Thats why stability with the bug on higher clocked phenoms is low.

    3GHz with stock voltage is not that bad imo. if the bug is removed and it woul run stable i would say it is rather good.

    Performance is indeed a bit low. Amd doesn't seem to get alot bennifit out the 128SSE2. wonder how that comes.
  • DrMrLordX - Monday, November 19, 2007 - link

    That's what the B3 stepping is supposedly intended to fix (among other things). Word is it will be available in January. More waiting!

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