AMD Bulldozer Thread

[xdan]

First of all, some people here who offended Monstru and lab501 should give apologies.
Even OBR need aplogies, he told the truth.
JF AMD should be banned for all his lies
Second the Bulldozer is a an EPIC FAIL, crap whatsoever


Why, let' see....

Very less IPC than Thuban even with 8 cores.

For a single instruction thread, Bulldozer offers more front end bandwidth than its predecessor. The front end is wider and just as capable so this makes sense. But note what happens when we scale up core count.
Since fetch and decode hardware is shared per module, and AMD counts each module as two cores, given an equivalent number of cores the old Phenom II actually offers a higher peak instruction fetch/decode rate than the FX. The theory is obviously that the situations where you're fetch/decode bound are infrequent enough to justify the sharing of hardware. AMD is correct for the most part. Many instructions can take multiple cycles to decode, and by switching between threads each cycle the pipelined front end hardware can be more efficiently utilized. It's only in unusually bursty situations where the front end can become a limit.

Compared to Intel's Core architecture however, AMD is at a disadvantage here. In the high-end offerings where Intel enables Hyper Threading, AMD has zero advantage as Intel can weave in instructions from two threads every clock. It's compared to the non-HT enabled Core CPUs that the advantage isn't so clear. Intel maintains a higher instantaneous decode bandwidth per clock, however overall decoder utilization could go down as a result of only being able to fill each fetch queue from a single thread.

So that's the 180% performance scale using CMT compared to Intel HT.
In fact 2cores(1 module) has less performance than Intel 1core+ HT. Performance may be 80%

The numbers in this table speak louder than words. The performance of Bulldozer microarchitecture has become way lower than that of the previous-generation processors. The simplification of Bulldozer microarchitecture by combining a pair of cores into a single module with shared resources led to a significant (25-40%) drop in specific performance compared with the previous-generation AMD microarchitecture. As a result, Bulldozer cores do not just work at half the speed of Sandy Bridge cores. In addition to that the performance of the Bulldozer processor module with two cores is even lower than that of a single Sandy Bridge core with enabled Hyper-Threading technology. Should we expect any performance records from a CPU with such microarchitecture? This is more of a rhetorical question…

Last drop which filled the cup...
Overclocking and power consumption....Performance/watt...

The results are shockingly bad to say the least. On overclocked full load, the power usage of the slower FX-8150 was nearly TWICE that of the faster i7-2600K. We haven't seen such monstrous power usages except in some dual socket systems or extreme overclocking (which ours isn't). We redid the tests multiple times using different motherboards and power measuring equipment but the results were the same everytime. Using a multimeter, the 12v rail on the extra 8+4pin CPU connectors also measured a whopping ~23A. With overclocked power loads like these, its no wonder AMD has to ship a water cooling solution together with the chip.