AMD's Next-Generation Mobile Architecture Revealed: Griffin
by Anand Lal Shimpi on May 18, 2007 12:10 AM EST- Posted in
- CPUs
New Memory Controller
Although the underlying architecture of Griffin is K8 based, the memory controller takes a lot of cues from Barcelona/Phenom. There's a new DRAM prefetcher, similar but not identical to what will be in Phenom, but many of the efficiency improvements in the new desktop core will make their way to Griffin as well. Taken from our Barcelona architecture article:
"One strength of Intel's FB-DIMM architecture used in Xeon servers is that you can execute read and write requests to the AMB simultaneously. With standard DDR2 memory, you can do one or the other, and there's a penalty for switching between the two types of operations. If you have a fairly random mixture of reads and writes you can waste a lot of time switching between the two rather than performing all of your reads sequentially then switching over to writes. The K8's memory controller made some allowances for preferring reads over writes since they take less time, but in Barcelona the memory controller is far more intelligent.
Now, instead of executing writes as soon as they show up, writes are stored in a buffer and once the buffer reaches a preset threshold the controller bursts the writes sequentially. What this avoids is the costly read/write switch penalty, helping improve bandwidth efficiency and reduce latency."
AMD did not make it clear whether Griffin also featured two independent 64-bit DDR2 memory controllers or a single 128-bit one. And, of course, as the memory controller is a part of the North Bridge it operates at a separate, lower voltage than the rest of the CPU cores.
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mesyn191 - Friday, May 18, 2007 - link
For the mobile space a cheap power efficient platform (not just a CPU but a NB/SB, wireless chipset, graphics, driver support, etc...) is far more important than sheer CPU performance.Griffin sure won't beat C2D on performance IPC or clockspeed wise but it will provide them with a viable low cost set of one size fits all tech. that they can sell to the OEM's and that is where the major volume (and thus money) is.
Haltech - Friday, May 18, 2007 - link
Unleess AMD thinks they can add Barcelona to the mobile market Intel will continue to add market share in mobile front. Plus it seems like their implying ATI graphics only when talking about discrete graphics.One question- why 6 sata ports and 14 usb ports...
tygrus - Sunday, May 20, 2007 - link
Using desktop chipset becomes a problem of overkill, wasting silicon and power. Need to be slimmed down but that would still be more expensive due to smaller production.
How much power do they use when inactive ?
strikeback03 - Tuesday, May 22, 2007 - link
Are there any desktop chipsets that support 14 USB ports? I don't remember seeing any.JarredWalton - Friday, May 18, 2007 - link
There are plenty of notebook users that want decent performance with LOOOONG battery life. If AMD can provide better typical battery use, they could still make some waves. At present, Turion X2 is already competitive with C2D in low power states, but at load they fall behind. A few optimizations could help them in both areas.Lonyo - Friday, May 18, 2007 - link
But that won't really help them in a years time.Competing in 12 months with what Intel has today means than when Intel has moved on 12 months, they will likely be ahead again, so overall nothing will have changed, although the consumer will reap the benefits :)