AMD's latest and greatest integrated chipset, will end up faster than it currently is.
Tomorrow is the day that AMD will be officially releasing the new AMD 780G(RS780) chipset worldwide, after it was released only in China a while ago. Turns out that the Chinese got "broken" samples of the chipset, namely the A11 revision of the chipset; we're getting the A12 tomorrow, which also isn't quite ready, yet.
The first commercial A11 revision was available very soon for reviewers and motherboard manufacturers, but it lacks full UVD support, which offloads video processing tasks from the CPU to the graphics card; AMD branded it as the RS780C and sells them cheaper.
The "fixed" A12 revision of the chipset is already being sold in China, it features full UVD support and has an interesting performance, even more when overclocked.
The delay to launch it worldwide, earlier, was rumored to be because of the lack of driver Hybrid Crossfire support - which proved mostly true: the embargo on the technology was lifted today.
What AMD isn't telling it's potential customers is that there is a major issue with the current A12 silicon: it doesn't support HT 3.0. HT3.0 is marketed as a big feature of Phenom CPUs and the AM2+ socket because it provides support for a maximum speed of 2.6GHz, providing more bandwidth than the HT2.0 link which is limited to 1.0GHz, or 2000MT/s.
AMD guidance suggests that the HD3200 core embedded in the 780G chipset will benefit a great deal from the added bandwidth provided by HT3.0 - which currently clocks at 1.8GHz for current Phenom processors, an 80% increase. Since the memory controller of the system is in the processor itself, the 780G will rely on the the HT link to move data to and from the RAM, hence limiting performance in case of a slow link.
The lack of HT3.0 support will also affect overall system performance, although not by as much as it will for the integrated graphics core - users of dedicated graphics will not be as affected. The Hybrid Crossfire technology will certainly also improve both due to the added performance of the integrated core and the improvement in communication with the discrete card.
The reason why most testers aren't noticing this workaround is because AGESA, a part of the BIOS, is automatically reducing the link to 1GHz HT2.0 when it detects an A12 revision of the chipset. Nvidia's upcoming, competing, solutions will offer full HT3.0 compliance, with production starting this month.
Mass production of the new A13 silicon is only estimated to start in May. Until then the GeForce 8200 chipset from Nvidia will have a good chance of competing with the 780G for the title of top performing integrated graphics.
UPDATE:
The issue only applies to Phenom 9100e and 9150e processors: read the follow up
4 comments:
Why make stuff up like this to sell another product that isn't even out?
See the following:
http://www.hothardware.com/articles/AMD_780G_Chipset_and_Athlon_X2_4850e_Preview_/?page=11
Actually, this is simply untrue. Reviews started posting yesterday on that new 780G chipset and it's clear that HT3.0 *does* work. I'm not trying to be mean-spirited here , but Tiago, you should seriously question whoever you are getting this kind of information from. If it didn't work, don't you think that one or more of these websites (and these are *not* little websites) would have pointed this out?
Perfect example that it does work at Hot Hareware: http://www.hothardware.com/articleimages/Item1116/ht_perf.png
Both of you are correct.
I contacted some people and the issue seems to only apply to the Phenom 9100e and 9150e processors, which will run with an HT3.0 link at 1.6GHz. With these CPUs, the AGESA version 3.1.3 and up will automatically change the link to HT2.0 1Ghz.
For now, all other will be able to use an HT3.0 link up to 2.6GHz, depending on the processor.
There may be some kind of incompatibility, that won't go away with the B3 K10 revision that the 9150e is based on.
Nvidia's MCPs won't have the same issues with these low-end processors.
The issue wasn't if it was noticed to be working or not because only measuring the different HT speeds would show a strange, same, performance result. As I mentioned, the BIOS would let the higher setting be set but would transparently change it to a lower one.
I hadn't come across a review that tested HT speed differences, fortunately your feedback helped to clear up the matter.
Best regards.
Post a Comment