The Phenom II X4 810 & X3 720: AMD Gets DDR3 But Doesn't Need It
by Anand Lal Shimpi on February 9, 2009 12:00 AM EST- Posted in
- CPUs
Lower TDPs, Faster un-core, DDR3 Support: The new Phenom II
All of the CPUs launching today are Socket-AM3 compatible. If you remember from my original Phenom II article, a Socket-AM3 CPU can work in both AM3 and AM2+ motherboards. I made a cute little compatibility matrix for you guys:
| CPU/Motherboard | Socket-AM2 MB | Socket-AM2+ MB | Socket-AM3 MB |
| Socket-AM2 CPU | Yes | Yes | No |
| Socket-AM2+ CPU | Maybe | Yes | No |
| Socket-AM3 CPU | Maybe | Yes | Yes |
AMD carefully engineered its AM3 memory controller allowing it to operate in both DDR2 and DDR3 modes. Any AM3 CPU can thus work in either a Socket-AM3 motherboard with DDR3 memory, or in a Socket-AM2+ motherboard with DDR2 memory. Backwards compatibility with original Socket-AM2 motherboards is up to the motherboard vendor, AMD does not validate any AM3 CPUs in regular AM2 motherboards.
The new Socket-AM3. Socket-AM2/AM2+ CPUs won't fit in here. But AM3 CPUs will fit in AM2+ boards.
All of the Socket-AM3 Phenom II CPUs are 95W TDP parts, compared to 125W for the first two chips that launched in January. The other notable change is that all of the AM3 CPUs run their un-core (North Bridge + L3 cache) at 2.0GHz instead of 1.8GHz like the AM2+ Phenom II processors.
Socket-AM3 Motherboards: Don't Bother Yet
I've had a Socket-AM3 motherboard here for a while but honestly the performance just isn't worth it. While it's taken a while to get stability up to par with AM2+, overall system performance remains unaffected. The Socket-AM2+ to Socket-AM3 transition looks a lot like the Socket-939 to Socket-AM2 transition we saw back in 2006.
A Socket-AM3 CPU (left) vs. a Socket-AM2 CPU (right) Note the missing pins on the AM3 chip.
Thankfully AMD gives you the option to ugprade whenever you'd like. You can buy a Socket-AM3 CPU today and use it in either an AM2+ board or an AM3 board, provided there's proper BIOS support. DDR3 memory is still more expensive than DDR2 and offers no real world performance advantage even at DDR3-1333 speeds.
Note that Socket-AM3 CPUs will only officially support one DIMM per channel running at 1333MHz. You'll need to run at 1066MHz speeds if you're running four DIMMs. When DDR2 and DDR3 memory reach price parity at the end of this year, AMD will be in a good position to make the transition. But if you're buying today, find a good AM2+ board and some cheap DDR2 memory.
The Test
| Motherboard: | Intel DX58SO (Intel X58) Intel DX48BT2 (Intel X48) MSI DKA790GX Platinum (AMD 790GX) |
| Chipset: | Intel X48 Intel X58 AMD 790GX |
| Chipset Drivers: | Intel 9.1.1.1010 (Intel) AMD Catalyst 8.12 |
| Hard Disk: | Intel X25-M SSD (80GB) |
| Memory: | G.Skill DDR2-800 2 x 2GB (4-4-4-12) G.Skill DDR2-1066 2 x 2GB (5-5-5-15) Qimonda DDR3-1066 4 x 1GB (7-7-7-20) |
| Video Card: | eVGA GeForce GTX 280 |
| Video Drivers: | NVIDIA ForceWare 180.43 (Vista64) NVIDIA ForceWare 178.24 (Vista32) |
| Desktop Resolution: | 1920 x 1200 |
| OS: | Windows Vista Ultimate 32-bit (for SYSMark) Windows Vista Ultimate 64-bit |
Facebook
Twitter
RSS
77 Comments
View All Comments
Casper42 - Monday, February 9, 2009 - link
In the Sysmark benchmark results, you have the following comment:Against to its Intel competition, the Phenom II X3 720 falls short of the Core 2 Duo E7500 and the E8400. The X4 810 also falls short of one of its intended targets: the Q8200.
While the X3 720 does fall to the E7500 (didnt bother comparing against E8400), the second line about the X4 810 losing out to the Q8200 is totally unfounded. The Sysmark results have the AMD chip losing in only 1 test set and the AMD wimming in the other 4 or 5.
I would probably buy the Intel anyway in today's market, but you should at least keep your review as honest and accurate as possible.
Lokinhow - Monday, February 9, 2009 - link
I've seen some scores with the X4 810 at ~3.7GHz, but not with a 2.7GHz NB clock.That would be nice to see some benchmarks at this clock speeds to know what is the boost in performance with a so higher nb clock speed.
Including a simillar clocked Core2Duo would be very nice too.
ps: yeah, my english is not so great, so sorry if there is some gramatical erros ;D
TA152H - Monday, February 9, 2009 - link
I'm really surprised that no one there put any thought into testing the difference between the memory controller and L3 cache running at 2.0 GHz instead of 1.8 GHz.I mean, you have a BE edition, with the 940, so what would have prevented you from running at at, say 2.6 GHz, like the 920, putting them on the same platform, and then benching them so we could see the difference the "uncore" speed makes.
It's really an important consideration, because obviously AMD will be releasing Phenom II's at 2.8 and 3.0 GHz, with 2.0 GHz uncore speeds, on AM3, and it helps people make a decision whether to wait or not. With AM2+ is shackled with DDR2 (I don't buy that there's no difference between DDR2 and DDR3, especially when other websites have identified them to be roughly 2%), the degenerate speed of the uncore could exacerbate this issue.
My other question is, does the uncore on the 910, et al, still run at 2.0 GHz when running in the AM2, and AM2+ platforms? I don't see why it would, but anything is possible.
I think two sets of benchmarks would be interesting. An underclocked 940 (to 2.6 GHz) versus a 910 processor. One on an AM2+ (yes, it's obsolete, but people will still buy it for a while) with the exact same memory. This assumes, of course, the uncore runs at 2 GHz for the 910 on this platform. The other is the 940 in its obsolete platform running at 2.6 GHz, against the 910 running on the modern AM3 platform, with high performance memory. If you really want to be thorough, you can run the 910 on both the AM3 and AM2+, each with the best memory available for it. I think these would all be helpful.
jchan2 - Monday, February 9, 2009 - link
Any word if there will be a Phenom II Black Edition in the near future?WillR - Monday, February 9, 2009 - link
Do you mean another Phenom II Black Edition? Is the 940 not good enough for you?jchan2 - Monday, February 9, 2009 - link
Why not? Imagine the ghz you can gain if there was one. AMD did it before, why not now?jchan2 - Monday, February 9, 2009 - link
Nvm, didn't realize the 940 was already BEWillR - Tuesday, February 10, 2009 - link
Yep. And it makes sense imo for only the highest clocked quad core and the highest clocked tri core to be Black Editions rather than also having an 8xx BE. I've heard they should have a 990 BE out Q3 or Q4 this year.strikeback03 - Monday, February 9, 2009 - link
Such as the 720 Black Edition tested here?jchan2 - Monday, February 9, 2009 - link
Yeah, besides the 720 such as the 800 or 900 series.