AMD Socket-AM2: Same Performance, Faster Memory, Lower Power
by Anand Lal Shimpi on May 23, 2006 12:14 PM EST- Posted in
- CPUs
AM2 in Detail
Of course the most prominent feature of AMD's Socket-AM2 platform is the new socket and its support for DDR2 memory. As we've already mentioned, Socket-AM2 is a 940-pin socket that is keyed differently from the original 940-pin Athlon 64/Opteron sockets; only AM2 processors will physically fit into an AM2 motherboard.
Socket-939 (left) vs. Socket-AM2 (right)
Socket-939 |
Socket-AM2 |
 |
 |
One of the Athlon 64's strongest selling points continues to be its on-die memory controller, which has of course been significantly changed for the new Socket-AM2 platform. All AM2 CPUs feature a 128-bit wide DDR2 memory controller, compared to the 128-bit DDR memory controller that we've come to know from the Socket-939 platform. A DDR2 memory interface actually requires more pins than a DDR1 interface, but AMD was able to keep the AM2 pin count down by removing a large number of unnecessary pins on the Athlon 64's package. When the Socket-940/939 Athlon 64s were first designed, approximately 10% of their pins were redundant and could be removed in later designs. Not desiring to introduce a new socket as frequently as its competition had, AMD waited until Socket-AM2 to remove those unnecessary pins thus enabling a dual-channel DDR2 interface in virtually the same pin count as the earlier DDR1 equipped CPUs.
All of the Socket-AM2 CPUs support up to DDR2-667, but the AM2 Athlon 64 X2 and Athlon 64 FX models support up to DDR2-800. Since Socket-AM2 unifies AMD's desktop socket strategy, all Semprons, Athlon 64s, X2s and FX processors will feature this dual channel DDR2 memory controller.
Corsair partnered with AMD and NVIDIA for the Socket-AM2 and nForce 500 review kits
The lineup of Socket-AM2 processors being introduced today are in the table below:
| CPU | Clock Speed | L2 Cache Size | TDP | Price |
| AMD Athlon 64 FX-62 | 2.8GHz | 1MBx2 | 125W | $1031 |
| AMD Athlon 64 X2 5000+ | 2.6GHz | 512KBx2 | 89W | $696 |
| AMD Athlon 64 X2 4800+ | 2.4GHz | 1MBx2 | 89W | $645 |
| AMD Athlon 64 X2 4600+ | 2.4GHz | 512KBx2 | 89W | $558 |
| AMD Athlon 64 X2 4400+ | 2.2GHz | 1MBx2 | 89W | $470 |
| AMD Athlon 64 X2 4200+ | 2.2GHz | 512KBx2 | 89W | $365 |
| AMD Athlon 64 X2 4000+ | 2.0GHz | 1MBx2 | 89W | $328 |
| AMD Athlon 64 X2 3800+ | 2.0GHz | 512KBx2 | 89W | $303 |
| AMD Athlon 64 3800+ | 2.4GHz | 512KB | 62W | $290 |
| AMD Athlon 64 3500+ | 2.2GHz | 512KB | 62W | $189 |
| AMD Sempron 3600+ | 2.0GHz | 256KB | 62W | $123 |
| AMD Sempron 3500+ | 2.0GHz | 128KB | 62W | $109 |
| AMD Sempron 3400+ | 1.8GHz | 256KB | 62W | $97 |
| AMD Sempron 3200+ | 1.8GHz | 128KB | 62W | $87 |
| AMD Sempron 3000+ | 1.6GHz | 256KB | 62W | $77 |
There's basically no price premium for the new Socket-AM2 chips, encouraging a quick transition to AMD's new DDR2 platform.
You will also notice that none of the model numbers have changed, so an Athlon 64 X2 4800+ on Socket-AM2 has the same clock speed and L2 cache size as the Socket-939 version. Since AMD's model numbers haven't changed, you already know not to expect any major changes in performance with Socket-AM2. In fact, the only difference on the CPU side is the introduction of the new Athlon 64 FX-62, Athlon 64 X2 5000+ and Athlon 64 X2 4000+.
Facebook
Twitter
RSS
83 Comments
View All Comments
Griswold - Tuesday, May 23, 2006 - link
Sounds conceiveable indeed. Though, the latter option would probably blow TDP out of proportion on 90nm.
mlittl3 - Tuesday, May 23, 2006 - link
Yeah, that is a problem but Anand did say "trick up its sleeve" so maybe they have one last 90 nm manufacturing process that's better than today's. I've read some articles about L3 cache coming for AMD and one inquirer.net article (take with grain of salt) that says AMD will ramp clock speeds fast. Maybe the trick will have something to do with these factors. Who knows?darkdemyze - Tuesday, May 23, 2006 - link
Whatever it is I'm interested in reading about itRegs - Tuesday, May 23, 2006 - link
Whatever it is, it's going to be expensive.TrogdorJW - Tuesday, May 23, 2006 - link
Actually, I was sort of thinking that the "stopgap solution" might be to cut prices. God only knows that I would love to see a $200 X2 processor!Griswold - Tuesday, May 23, 2006 - link
Well, they will have to drop prices at some point after core 2 is actually available.xFlankerx - Tuesday, May 23, 2006 - link
Indeed, same results as expected. Maybe this will make the AMD fanboys shut up about "waiting to see what the final results are." NOTE: I have a AMD system, I'm simply addressing those that refuse to accept Conroe's superiority.Although...I must say that this "stop gap" solution by AMD has piqued my curiosity.
But I believe that these say it perfectly;
"One of its stipulations for sending out Socket-AM2 review kits was that the CPUs not be compared to Conroe."
"We do get a sense of concern whenever Conroe is brought up around AMD."
"So when Intel first started talking about its new Core architecture, we turned to AMD for a response that it surely must have had in the works for years, but as you all know we came up empty handed."
Those just say it all for me. Seems like AMD's in trouble. From what I've been reading, K8L doesn't bring in architectural changes either. Sure you get Quad Cores, L3 cache, FB-DIMM support, DDR3, and faster HyperTransport, but if AMD doesn't improve on it's performance-per-clock efficiency, then Intel's Quad Cores (due almost 9 months before AMD's) are going to rule supreme yet again.
Griswold - Tuesday, May 23, 2006 - link
Maybe read up on it first.
Memory mirroring, data poisoning, HT retry protocol support, doubled prefetch size (32byte instead of 16), 2x 128bit SSE units (instead of 2x 64bit), out of order load execution, Indirect branch predictors and a handful new instructions sure sounds like a few architectural changes and not just a simple revision stepping.
rADo2 - Tuesday, May 23, 2006 - link
Sorry, links again:Intel Conroe @ 3.9GHz: SuperPI 1M - 12.984s
http://www.xtremesystems.org/forums/showthread.php...">http://www.xtremesystems.org/forums/showthread.php...
AMD FX-57 @ 4.2GHz: SuperPI 1M - 21.992s
http://www.xtremesystems.org/forums/showthread.php...">http://www.xtremesystems.org/forums/showthread.php...
MadAd - Monday, May 29, 2006 - link
Try measuring like for like and then come back with your silly benchmark comparison. EG use a superpi data size that will fit on BOTH cpus caches, not just conroes and then compare performance.With the FX57 having just a 1M cache its bullsht smoke and mirrors saying the 1M superpi is slower, o rly? perhaps thats because it takes more than 1M to hold both the feature and data sets on a 1M superpi.
muppet