The AMD FX (Bulldozer) Scheduling Hotfixes Tested
by Anand Lal Shimpi on January 27, 2012 12:47 PM ESTFinal Words
AMD didn't overpromise as far as the benefits of these new scheduling/core parking hotfixes for Windows 7 are concerned. Single digit percentage gains can be expected in most mixed workloads, although there's a chance that you'd see low double digit gains if the conditions are right. It's important to note that the hotfixes for Windows 7 aren't ideal either. They simply force threads to be scheduled on empty modules first rather than idle cores on occupied modules. To properly utilize Bulldozer's architecture we'd need a scheduler that schedules both based on available cores/modules but biases its scheduling depending on data dependency between threads.
If Bulldozer were the last architecture to present this type of scheduling challenge I'd say that it's unlikely we'll see things get better. Luckily for AMD, I don't believe homogeneous multi-core architectures will be all we get moving forward. Schedulers will get better at understanding the underlying hardware, just as they have in the past. We may see better utilization of Bulldozer cores/modules in Windows 8 but as always, don't use the promise of what may come as a basis for any present day purchasing decisions.
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Beenthere - Friday, January 27, 2012 - link
The Hot Fix is better than No Fix and Win 8 beta looks to be a few percent better than the Win 7 Hot Fix. So it's all good but nothing startling. Combined with Vishera/Piledriver should provide a nice performance bump however.Ramon Zarat - Friday, January 27, 2012 - link
"The Hot Fix is better than No Fix".No...
A fix than bring no additional value (less than 2%, well below statistical significant value), and at the same time, by its simple presence, introduce the potential of conflict and instability (simple law of entropy) can only be detrimental to a system, not positive.
Another way to look at it: If my car is broken to the point of being unusable and I apply 1500$ worth of parts and labor and in the end it make no difference in its usability, why spend the 1500.00$ in the first place? New parts are better than no new parts?
I love AMD as a company, I really do. The truth is Bulldozer in conjecture with present operating system is broken and dysfunctional with embarrassing sub-par performance and inacceptable power consumption per instruction for what is supposedly a 8 cores CPU that cannot even approach a 4 cores 2500K performance in 90% of scenarios. AFAIK, that applies to ALL operating system including Linux and Mac. I even have my doubt a perfectly Bulldozer tuned OS would be able to compete with Intel offering. I'd like nothing better to be proved wrong on that one.
AMD knew from day 1 (years ago) that their new unconventional architecture would face issue such as this one, but it’s only now, months after the actual launch of the product that they are working on fixes that fix nothing? Great example of bad management / strategy / planning and lack of foresight from AMD. I hope they have learned a lesson because underdog can’t afford such huge misstep too often and hope to stay alive in the long run.
bigboxes - Friday, January 27, 2012 - link
But can I download more torrents with this fix?ThomasS31 - Friday, January 27, 2012 - link
Why you have not tested core usage / clock gating and power consumption?I thouht the main problem of scheduling related to that as well...
Lugaidster - Friday, January 27, 2012 - link
This!Is power consumption altered with this hotfix?
Cheers
MrSpadge - Sunday, January 29, 2012 - link
Power consumption for given "mixed workloads" should be altered.. increased, actually, since more modules are active. Overall energy consumption, on the other hand.. I don't know. More power draw but for a shorter time.MrS
Marlin1975 - Friday, January 27, 2012 - link
Anybody notice the differance between the first hotfix and the 2nd?The first one even helped some Intel CPUs. The 2nd one seems to not help either AMD or Intel as much???
saneblane - Friday, January 27, 2012 - link
I fail to see what was fixed, i give them credit for adding 2 more fps in x264 second pass. But come on this is just stupid. their is no performance increase that is going to be noticed or seen by this so called hot fix. We already accept the fact that bulldozer failed on the desktop in it's first showing, why remind us again. Things like this make people lose confidence in you, just lay low and try to improve Piledriver.Lonyo - Friday, January 27, 2012 - link
Because this won't probably help future AMD CPUs?It's something Microsoft will need to deal with, and possibly already have with Win 8. It's free performance, and it helps pretty much test future similarly equipped AMD CPUs.
What are they supposed to be doing, other than giving free performance gains to Bulldozer users?
saneblane - Friday, January 27, 2012 - link
well if you think the hotfix is worth wild, then i guess AMD has done it's job. Their is always more people that are easily fooled than the ones who can see the truth. Free performance??? Give me a freaking break, i waited years for bulldozer, and your going to tell me about a cpu that cost more than an i5 2500 and losses in almost every benchmark and games.That this hotix is free perfomance, haha. Zambezi users are paying a lot for this so called "free" when even i5 2500 beat the crap out of it, i guess sandy bridge has a lot of "free" performance too.