i5 / i7 MBP / Logic Pro benchmark test

I was incorrect in saying it was an old xeon without hyperthreading. It was bought a while ago, but like I said it definitely shows more cores in activity monitor than the physical amount it actually has, and it does the same in logic. It must be 8 then, like I said I've been away from the studio for a while on, let's call it sick leave.
In any case, I suppose my point still stands too. HT does appear to give you real, actual CPU bars in Logic that process real actual threads just like they were real actual cores.. It's not some vague CPU enhancement that happens in the background, it really is as if your 4 physical core xeon is actually an 8 physical core one. And this is precisely what is (currently) missing from the mobile i5 and i7 used in the new MacBook Pros, they seem to do the HT thing at system level, but Logic doesn't seem to be able to use it like it does on the xeons. I really think this is just an update thing, because it seems obvious that the architecture of these CPUs must be slightly different to xeons and so some kind of adjustment must be needed before Logic can use it just like it does on the Mac Pros. After all, it says hyper threading in the advertised specs, so there should be no technical reason why if Logic can make use of it on a Mac Pro, it can't on a Macbook Pro with a CPU that supports the very same technology.

http://www.macobserver.com/tmo/article/thenew_macbook_pros_1517-inch_are_not_quadcore/

As mentioned, looks like Logic is seeing only the two physical cores.

pancenter-

Pancenter wrote:
http://www.macobserver.com/tmo/article/thenew_macbook_pros_1517-inch_are_not_quadcore/

As mentioned, looks like Logic is seeing only the two physical cores.

pancenter-

...for now, yes. But we already know that Logic itself is able to see 4 (or more) virtual cores on different CPU architectures. So I'd expect the situation for the mobile i5/i7 will change in due course such that we'll see 4 CPU bars in Logic on the new MBPs fairly soon.

tbirdparis wrote:

Pancenter wrote:
http://www.macobserver.com/tmo/article/thenew_macbook_pros_1517-inch_are_not_quadcore/

As mentioned, looks like Logic is seeing only the two physical cores.

pancenter-

...for now, yes. But we already know that Logic itself is able to see 4 (or more) virtual cores on different CPU architectures. So I'd expect the situation for the mobile i5/i7 will change in due course such that we'll see 4 CPU bars in Logic on the new MBPs fairly soon.

If Apple follows through with all machines in regards to Logic, then the Octo-core Macs will show 16 cores, Quad-core Macs 8 cores and Duo-core Macs will show 4 cores. As it stands right now, the only Mac that shows both physical and virtual cores are the Quad-core with HT and this is because Apple has limited Logic to showing 8 cores max. There was a version of Logic (9.01?) that showed 16 cores on an Octo-core HT machine but that was changed back to 8 with the next update.

There's some references here.
Funny how people dismiss Blueberry.... ahem!

http://discussions.apple.com/thread.jspa?messageID=10778772&#10778772

pancenter-

Pancenter wrote:

tbirdparis wrote:

Pancenter wrote:
http://www.macobserver.com/tmo/article/thenew_macbook_pros_1517-inch_are_not_quadcore/

As mentioned, looks like Logic is seeing only the two physical cores.

pancenter-

Sure, I agree. So it should be no issue for the mobile i5/i7 in the new MBPs to show the 4 virtual cores that they are capable of using. Activity Monitor shows it, so if Logic Pro is actually using the Hyper Threading capability of these CPUs, its CPU bars should show it too.

Given that the actual performance figures people are reporting are showing not as big a jump in performance on the i5/i7 with regards to Logic performance over the previous Core 2 Duo generation as would be expected if 4 virtual cores were being exploited, this implies that Logic may currently not be using HT +at all+ on these MBPs.

A simple explanation for this seems to be that, even though Hyper Threading is an advertised feature of these CPUs and it works on an OS level, Logic Pro is currently missing some extra bit of code to be able to use it like it does on other CPU architectures. Given the evidence, this seems to be a reasonable theory to suggest so I'm not sure exactly what it is you're saying.

In any case, I've filed a bug report with Apple on this and am waiting on word on the matter from some engineers who may be in a position to actually chase this up. I don't care whether I am actually shown 4 CPU bars in Logic or 2. I just want to know one way or the other if Hyper Threading, an advertised hardware feature of the mobile i5/i7 in the new MBPs, is actually being used by Logic, or not. Doesn't matter to me in the slightest if I only ever see 2 CPU bars, I don't need to actually see that there are 4 virtual cores being used to process threads. But I am interested in making sure that the hardware is being used to its full extent, that's all.

...for now, yes. But we already know that Logic itself is able to see 4 (or more) virtual cores on different CPU architectures. So I'd expect the situation for the mobile i5/i7 will change in due course such that we'll see 4 CPU bars in Logic on the new MBPs fairly soon.

If Apple follows through with all machines in regards to Logic, then the Octo-core Macs will show 16 cores, Quad-core Macs 8 cores and Duo-core Macs will show 4 cores. As it stands right now, the only Mac that shows both physical and virtual cores are the Quad-core with HT and this is because Apple has limited Logic to showing 8 cores max. There was a version of Logic (9.01?) that showed 16 cores on an Octo-core HT machine but that was changed back to 8 with the next update.

pancenter-

tbirdparis wrote:
In any case, I've filed a bug report with Apple on this and am waiting on word on the matter from some engineers who may be in a position to actually chase this up. I don't care whether I am actually shown 4 CPU bars in Logic or 2. I just want to know one way or the other if Hyper Threading, an advertised hardware feature of the mobile i5/i7 in the new MBPs, is actually being used by Logic, or not. Doesn't matter to me in the slightest if I only ever see 2 CPU bars, I don't need to actually see that there are 4 virtual cores being used to process threads. But I am interested in making sure that the hardware is being used to its full extent, that's all.

Thanks for doing this, I admit to being curious as to how HT cores can be used in Logic, especially on single thread processes like a single channel strip with VI and FX. Maybe it's done at the OS level, which would be a feature of Snow Leopard as it sure didn't work like that on Leopard.

pancenter-

Pancenter wrote:

tbirdparis wrote:
In any case, I've filed a bug report with Apple on this and am waiting on word on the matter from some engineers who may be in a position to actually chase this up. I don't care whether I am actually shown 4 CPU bars in Logic or 2. I just want to know one way or the other if Hyper Threading, an advertised hardware feature of the mobile i5/i7 in the new MBPs, is actually being used by Logic, or not. Doesn't matter to me in the slightest if I only ever see 2 CPU bars, I don't need to actually see that there are 4 virtual cores being used to process threads. But I am interested in making sure that the hardware is being used to its full extent, that's all.

Thanks for doing this, I admit to being curious as to how HT cores can be used in Logic, especially on single thread processes like a single channel strip with VI and FX. Maybe it's done at the OS level, which would be a feature of Snow Leopard as it sure didn't work like that on Leopard.

pancenter-

I think it's even simpler than that. With Hyper Threading, as far as the computer is concerned, it actually simply has 2 cores per physical core that actually exists. This is because of something to do with something technical-sounding like 'long pipelines' or something like that.. So, a core gets given threads to process, and it pretends to be 2 cores instead of one because it can divide the threads one at a time down two separate pipelines or something like that. So in effect, no it's not quite as fast as having two real actual cores doing the crunching.. but, it absolutely acts as if it were two separate cores, meaning that it can take on a VI and a plug in at the same time, dividing them up as though they had their own core to run on. So in terms of parallelism, it's functionally identical to having multiple real physical cores with all the advantages that this brings. It's only a little slower than the equivalent amount of cores doing the same thing if they were all actual physical ones, because CPU time is being shared. But apparently because of this long pipeline thingy, this split processing is much faster than you'd think it would be if you're just imagining a CPU sharing its time evenly between one thread and the next.

Look, my understanding of it is rudimentary to say the least. But the basic principle is such that Logic Pro on an i5 or i7 MBP should absolutely, definitely behave like a quad core, with of course a slight penalty vs an equivalent CPU that actually is a quad core. In any case, let's wait and see what happens on this front. People seem to have been getting performance results in Logic on the new i7 MBPs that aren't as much faster as they should be compared to a Core 2 Duo, if Hyper Threading was really being used. So this is why my suspicion is that the architecture of these CPUs is slightly different to Xeons and so Logic isn't tweaked yet to take advantage of it. OSX 10.6.3 definitely does, because you open Activity Monitor, and you see the four CPU bars right there on your screen. My feeling is that there's just an adjustment or two needed to enable the full use of Hyper Threading by Logic (which may come in a Logic update, or a Pro Kit or Pro App Support update), at which point we'll see a jump in Logic performance that reflects the same jump you already see in simple benchmark tests. I'm almost certain that this must be the case, because if the i7 is reporting x amount of a speed bump over the previous core 2 duos, and yet the performance increase specifically for Logic is nowhere near in that same range.. then this must be why.

So I've done the bug report and also mentioned it at Logic feedback, and again I encourage anyone else who is interested in this to do the same. I asked for them to at least put out a KB article explaining Logic and the mobile i5/i7, so at least we know what the story is.

Like I said, you look at the benchmarks and they don't add up. In simple terms - the MBP i7 shows a much bigger number when you run a geekbench CPU test on it compared to a Core 2 Duo. And yet that huge speed difference does not seem to correspond to the amount of extra plug ins etc that Logic can run, so that tells me something is missing in the equation. Another giveaway for me is that in the past, Apple have often put up a comparison chart showing real-world(ish) figures of how the performance has improved for all of the Pro Apps when they release a new series of Mac Pro or MacBook Pro. For this release, the usual comparison chart showing how many reverb plug ins or whatever in Logic Pro is suspiciously absent. So, they either just overlooked it or decided not to put that up on the site this time.. or, they intentionally skipped over it because they know that for the moment, Hyper Threading is an advertisable feature for this series of machine at least in terms of being used by OSX, but that Logic Pro currently doesn't use it. So rather than putting up a lukewarm comparison chart that only showed a slight edge in Logic performance (which would have looked completely out of whack with the quite significant boost these machines show in overall speed), they may have decided to just not mention it at all for now.. until the code adjustments are made such that Logic can actually use the Hyper Threading feature which is probably a little different in architecture to how it is in the Xeons. Anyway like I said.. we'll see. I still like my i7 and I personally haven't even had the chance to see how it performs yet at all.. so when I do, I might find that it really already is a lot faster, although it seems that people are discovering the contrary to be true.

This is text from the link I posted. I would imagine this is true of third party DSP effects as well.

This is a reliable source btw.

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"With hyperthreading the math unit (FPU) in one core is shared between two hyperthreads. But because Logic's DSP code is heavily based on math, hyperthreading doesn't gain you any actual performance, because the hyperthreads have to continously switch the state of the one FPU. However other threads in the system might gain a bit by the hyperthreads."
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Perhaps this has changed in the few months since this was posted, I don't know.

pancenter-

djanthonyw wrote:
http://www.gearslutz.com/board/5400725-post538.html

But if tbirdparis is correct, Logic just needs to me modified to use the two virtual HT cores.

Unless that's not possible with the mobile processors.

pancenter-

Pancenter wrote:
http://www.macobserver.com/tmo/article/thenew_macbook_pros_1517-inch_are_not_quadcore/

As mentioned, looks like Logic is seeing only the two physical cores.

Which is a drag because the machine also has two partial HT cores, and on most other machines Logic sees them and uses them. Hopefully that will be fixed soon and they will show four cores as they should.

Pancenter wrote:
I admit to being curious as to how HT cores can be used in Logic, especially on single thread processes like a single channel strip with VI and FX. Maybe it's done at the OS level, which would be a feature of Snow Leopard as it sure didn't work like that on Leopard.

My guess is that it sends a thread to each core, whether it's a HT core or a full core.

People tend to call HT cores "virtual" as if they are just some sort of simulation but they are actual physical cores, just partial ones. These chips actually do have four physical cores, it's just that two of the cores aren't complete cores and have to share some computational bits with the other two cores.

Glad to hear that people are filing bug reports on this, it's definitely a case where something isn't working right.

I was wondering if the issue for the MacBook Pro i5 and i7 with the number of tracks they can handle has in anyway improved with the recent OSX update to 10.6.4. Feedback really appreciated on this...

I was considering upgrading to a new MBP i5 or i7 but after this discussion thread am completely put off the idea. I am flying into the US in a week for a brief visit and since Mac's area cheaper in the USA I was tempted to get one, if it has been resolved. So an answer from a kind soul who has a i5 or i7 MBP would be really appreciated as a timely reply is critical for me.

Logic is the only reason I am maxing my 2.33 C2D - I use no other software that currently is a major issue for needing more horsepower...

Thanks!!