AMD's Phenom Unveiled: A Somber Farewell to K8
by Anand Lal Shimpi on November 19, 2007 1:25 AM EST- Posted in
- CPUs
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.
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Iketh - Wednesday, November 21, 2007 - link
damn where is the rating system??!!strikeback03 - Wednesday, November 21, 2007 - link
If you read the graphs, you will see they are testing total system power draw. Typically they test at the wall with a Kill-A-Watt meter, though this article does not explicitly state that.Assuming the other components were the same between systems, this number then shows the difference in Processor + chipset power consumption between the platforms.
Barcelona is the name of the server processor, ( http://www.anandtech.com/IT/showdoc.aspx?i=3099">http://www.anandtech.com/IT/showdoc.aspx?i=3099 ) is one test. Intel power consumption is pretty much screwed by use of the FB-DIMMs.
cyborgtrader - Monday, November 19, 2007 - link
The comments on this topic were great. AMD really let us down on this one. I trade Intel stock, but only buy AMD chips and today I am so dissapointed. I hope AMD read these reviews and get their act together. Patience is a virtue, so I am going to wait for another review after better yeilds have been produced. Guess I can tuck my cash back into my wallet.mmmm, Maybe AMD was joking with this chip. Could Santa be delivering the real Quad? With this reveiew we better hope so.
ct
eye smite - Tuesday, November 20, 2007 - link
I hope all of you choke on your comments. You're completely judging amd on pre production samples that will all mature and give more accurate benchmarks by the time they hit stores. No it's not a core 2 killer but amd never planned for it to be. They laid out a road map some time back and are following it as best they can with the resources they have. It's the first native quad core, intel can't say that. It's brand new, so it's full potential hasn't been seen and probably fully developed yet. You gobshites are just like the rest of America I have to live with everyday and want it NOW. You sound like a bunch of 2 yr olds screaming mine mine.strikeback03 - Wednesday, November 21, 2007 - link
Anand stated that AMD has promised availability by the end of the week, so unless they shipped him below-average samples to test, this is indeed representative of what will hit stores at first. AMD may or may not have planned it as a Core 2 killer, but if Intel outperforms them on speed and power usage at the same prices, who is gonna buy AMD? Being the first native quad-core is an interesting Trivial Pursuit fact, but it won't win many sales unless performance goes up or price goes down.Screammit - Wednesday, November 21, 2007 - link
All we can do as consumers is make educated choices based on the information we can get.Your arguement is "wait and see," which is not a bad position to take, but this is the first TANGIBLE evidence of what AMD can do with its new chips, which most of us have been waiting over a year for. The information we have right now says that the current best AMD quad core chip can't compete in performance with the slowest intel based quad core, which if our information is correct, will cost the same.
By comparison, you can see the first time Anand got a hand on a test sample of Conroe, the results eventually foreshadowed real world performance:
casket - Tuesday, November 20, 2007 - link
I wonder what happened on this test?http://www.tomshardware.com/2007/11/19/the_spider_...">http://www.tomshardware.com/2007/11/19/the_spider_...
Iketh - Thursday, November 22, 2007 - link
the same way cpuz showed the phenom as single-channel memory, this sandra test is probably showing the result from 1 of the memory controllers... thus both channels together are undoubtedly pumping out 10000+, which makes a LOT more sensesdmock - Tuesday, November 20, 2007 - link
So apparently AMD's chips have higher memory bandwidth for integers and FPs. But so what if it ain't faster?stmok - Monday, November 19, 2007 - link
I've waited for Phenom as a potential upgrade to my current three systems (Socket 754 Semprons, AMD64).