iMac Core 2 Duo Benchmarks

[AidenShaw]

reliable?

Probably Apple's most impressive, solid and reliable machine at the moment

I don't think that there's any data yet on failure rates and problems with the new Core 2 iMacs...

 

[50548]

Good - now we won't have to wade through any arguments with fanbois who claim that the iMac is the "most powerful desktop on the planet"....

As previously confirmed, the iMac is the most powerful AIO desktop...the title you just mentioned belongs to the MacPro...sorry for the misunderstanding...

How is Winblows going on your side, Aiden? Many BSODs today?

PowerBooks G5, oops, Mini Tower Macs next Tuesday!!!!

 

[50548]

I don't think that there's any data yet on failure rates and problems with the new Core 2 iMacs...

He is talking about reliability data from at least the last 10 years, Aiden...data you must have no clue about, of course...after all, Macs just started doing Windows, right?

 

[Homy]

I'm just not sure why everyone is so impressed with these imacs.

Faster processor, double the RAM, cheaper AND 21-37% better game performance:

New 17" C2D is 37% faster in UT 2004 than old 17" CD.
New 17" C2D is 21% faster in UT 2004 than old 20" CD.
New 20" C2D is 37.5% faster in UT 2004 than old 20" CD.

and I don't even play UT 2004 .

 

[MattyMac]

I want to see some unpacking pics of that 24inch model compared with the 20in. Soon enough I suppose.

 

[ezekielrage_99]

Faster processor, double the RAM, cheaper AND 21-37% better game performance:

New 17" C2D is 37% faster in UT 2004 than old 17" CD.
New 17" C2D is 21% faster in UT 2004 than old 20" CD.
New 20" C2D is 37.5% faster in UT 2004 than old 20" CD.

and I don't even play UT 2004 .

I think more than anything the facts that they are cheaper and faster the previous models are more impressive than anything else and with tempt a lot of people to join the "dark side" of Mac.

 

[AidenShaw]

Unless Leopard is designed to make full use of the extra threads/cores available on the quad-core Mac Pro.

The real problem isn't the OS as much as it is in applications.

A well-threaded O/S won't help make Photoshop or Avid run much faster, unless the application code is also able to use all of the cores that are present.

Some applications are inherently serial - you have to do step A, then step B (because step B depends on step A). It's not a matter of poor programming, it's that the task is serial. (Note that many Photoshop benchmarks quote "MP-aware" filters separately from actions that don't scale.)

For these "not well-threaded" applications, multiple cores will still be beneficial so that you can run multiple applications simultaneously - all at full speed.

There are some server-type applications (web or database) that run many (hundreds or thousands) threads simultaneously. (For a web server - each browser session is a natural thread.) For these applications, operating system efficiency is important. The reports that OSX is poor at threading (such as Mac OS X limits server performance) aren't really that important for desktop apps that want to use all 4 cores (or soon 8).


http://www.anandtech.com/mac/showdoc.aspx?i=2436

The server performance of the Apple platform is, however, catastrophic.
...
Workstation apps will hardly mind, but the performance of server applications depends greatly on the threading, signalling and locking engine.​

 

[Mikael]

The fact that the new iMacs can't address more than 3Gb of memory and are therefore operating on a 32bit logic-board makes me doubtful as to whether or not these systems are really 64-bit capable... It seems like some kind of hybrid 32/64bit system.

Will the C2D iMacs be able to run 64bit code, despite not having the 64bit address space (and being able to access over 4Gb or RAM)?

I've searched for address bus width for the Core 2 line, but haven't found anything. It is, however, not likely that Intel downgraded the width from the previous models, which would mean either a 36 or a 40 bit bus. Also note that AMD's K8 (Athlon 64, Sempron and Opteron) also feature a 40 bit address bus and not 64 as someone might think. I also think that the G5 uses a 40 or 42 bit address bus, so it's pretty much the same there too.

So, if Core 2 has a 40 bit bus (which is likely) you end up with 1TB of addressable memory space.

Also, Core 2 CPUs are fully capable of running 64 bit code. Whether the address bus is 64 bits wide or not hasn't got anything to do with the width of the internal data path and execution unit width.

 

[Manic Mouse]

The real problem isn't the OS as much as it is in applications.

A well-threaded O/S won't help make Photoshop or Avid run much faster, unless the application code is also able to use all of the cores that are present.

Some applications are inherently serial - you have to do step A, then step B (because step B depends on step A). It's not a matter of poor programming, it's that the task is serial. (Note that many Photoshop benchmarks quote "MP-aware" filters separately from actions that don't scale.)

For these "not well-threaded" applications, multiple cores will still be beneficial so that you can run multiple applications simultaneously - all at full speed.

There are some server-type applications (web or database) that run many (hundreds or thousands) threads simultaneously. (For a web server - each browser session is a natural thread.) For these applications, operating system efficiency is important. The reports that OSX is poor at threading (such as Mac OS X limits server performance) aren't really that important for desktop apps that want to use all 4 cores (or soon 8).


http://www.anandtech.com/mac/showdoc.aspx?i=2436

The server performance of the Apple platform is, however, catastrophic.
...
Workstation apps will hardly mind, but the performance of server applications depends greatly on the threading, signalling and locking engine.​

Ahh. Nice info Aiden, thanks for that!

[QUOTE="BRLAWYER]Many BSODs today?[/QUOTE]

I must be one of the few windows users who has never seen a BSOD since Win 95...

I've been using the Vista Beta 2 exclusively since it's release and it's apparently a very unstable OS yet I haven't seen a single BSOD. Looking forward to upgrading to RC1 and all the performance improvements that will bring though!

What I'm wondering is how Leopard will change the performance of the iMacs and Mac Pros. Will having a full 64-bit operating system and applications mean they run faster, or will the end-user see little difference?

 

[Evangelion]

The fact that the new iMacs can't address more than 3Gb of memory and are therefore operating on a 32bit logic-board makes me doubtful as to whether or not these systems are really 64-bit capable... It seems like some kind of hybrid 32/64bit system.

Will the C2D iMacs be able to run 64bit code, despite not having the 64bit address space (and being able to access over 4Gb or RAM)?

Uh.... The CPU is 64bits, and it DOES have 64bits address-space. And it runs 64bit code just fine. It just happens that the rest of the system it's hooked up to does not support 4+GB of RAM. But that has NOTHING to do with the "bitness" of the CPU. C2D is a 64bit CPU, period.

Hell,there has been 64bit CPU's and machines for long time (SGI and Sun comes to mind), yet back in those days even 1GB of RAM would have cost an arm and a leg. Yet those machines were 64bit machines.

As to logic-board being 32bits... Uh, no. There might be various reasons why it doesn't support 4GB of RAM, and it isn't due to "bitness" of the logic-board. And pray-tell: what exactly is a "32bit logic-board"?

 

[Manic Mouse]

I've searched for address bus width for the Core 2 line, but haven't found anything. It is, however, not likely that Intel downgraded the width from the previous models, which would mean either a 36 or a 40 bit bus. Also note that AMD's K8 (Athlon 64, Sempron and Opteron) also feature a 40 bit address bus and not 64 as someone might think. I also think that the G5 uses a 40 or 42 bit address bus, so it's pretty much the same there too.

So, if Core 2 has a 40 bit bus (which is likely) you end up with 1TB of addressable memory space.

Also, Core 2 CPUs are fully capable of running 64 bit code. Whether the address bus is 64 bits wide or not hasn't got anything to do with the width of the internal data path and execution unit width.

Thanks

To be honest I'm not all that well versed in the differences between 64bit and 32bit computing...

 

[AidenShaw]

He is talking about reliability data from at least the last 10 years, Aiden...

You mean Powerbook hinges, iBook logic boards, MacBook Random Shutdown Syndrome (RSS), eMac logic boards, Powerbook memory slot, White spots and lines on Powerbook screens, chipping paint, cracked cubes, iMac G5 video and power problems,Apple repair extensions,...

I see your point!

 

[Evangelion]

As previously confirmed, the iMac is the most powerful AIO desktop...the title you just mentioned belongs to the MacPro...sorry for the misunderstanding...

You again with your ludicrous claims? What makes you think that Mac Pro is the fastest desktop there is? What is the secret ingredient that makes it faster than other machines, considering that it uses same components than others do? And since Mac Pro supports less RAM (16GB vs. 64GB) than Dell does (for example), how could you say that it's "the most powerful"? Compared to Dell, it will be dog-slow for tasks that require a lot of RAM.

How is Winblows going on your side, Aiden? Many BSODs today?

Now, I hate Windows and I use it at work because I have no choice. An there are plenty of bad things in it. But I don't get any BSODs. I really don't. Back when I used a desktop, I sometimes left the machine running for weeks and I had no problems.

When was the last time you used Windows? Back in Windows ME-days?

Seriously: I think you should take a chill-pill an dial-back that fanboyishness of yours.

 

[steve_hill4]

The last revision of the iMac G5 (the one with the iSight) had the option of 2.5GB of RAM. It had 512MB built-in and you could option a 2GB stick for the 1 open slot it had.

That 2GB of course cost an arm and a leg...

That's right actually, it was 512MB soldered and a single slot wasn't it? I also thought for a short time after the new C2D iMacs were announced and it said max. 3GB, 1GB would be soldered and there would be a single 2GB slot or two 1GB slots.

Some good points have been raised on the 64-bit OS front. Since Leopard will fully support 64-bit down to the kernal, I would hope this first 64-bit Intel iMac would benefit as much as the Mac Pro.

However, does anyone know for sure whether a) the OS X on the new iMacs is 64-bit and/or b) whether OS X on Intel has even been translated to 64-bit, (thinking Mac Pro here too)? It's something I have yet to bother looking into, but any answers here would be appreciated.

 

[Manic Mouse]

Uh.... The CPU is 64bits, and it DOES have 64bits address-space. And it runs 64bit code just fine. It just happens that the rest of the system it's hooked up to does not support 4+GB of RAM. But that has NOTHING to do with the "bitness" of the CPU. C2D is a 64bit CPU, period.

Hell,there has been 64bit CPU's and machines for long time (SGI and Sun comes to mind), yet back in those days even 1GB of RAM would have cost an arm and a leg. Yet those machines were 64bit machines.

As to logic-board being 32bits... Uh, no. There might be various reasons why it doesn't support 4GB of RAM, and it isn't due to "bitness" of the logic-board. And pray-tell: what exactly is a "32bit logic-board"?

Sorry, that post was just me airing my thoughts and seeing what other people had to say. I wasn't making any claims, I don't know a lot about 64-bit computing. Glad my ignorant thoughts turned out to be wrong though!

I just assumed that being 64-bit or 32-bit was a system wide principle, either or.

 

[steve_hill4]

Now, I hate Windows and I use it at work because I have no choice. An there are plenty of bad things in it. But I don't get any BSODs. I really don't. Back when I used a desktop, I sometimes left the machine running for weeks and I had no problems.

When was the last time you used Windows? Back in Windows ME-days?

I have had a few BSODs in XP, but they are rare. Mainly I used to leave my tower on 24/7 and the worst I would get is switching my monitor on first thing in the morning or when I got home from work and see it had rebooted itself and was telling me it was an invalid system disc.

Since Mac, never once has this happened, (even though I tend to power down on this more often, I still often leave running 24/7 if it is doing something that requires up time).

Strangely enough, I am one fo the few that never had that many problems with ME.

 

[AidenShaw]

As to logic-board being 32bits... Uh, no. There might be various reasons why it doesn't support 4GB of RAM, and it isn't due to "bitness" of the logic-board. And pray-tell: what exactly is a "32bit logic-board"?

The Napa chipset used with Yonah only supported 32 address lines.

A new Napa64 chipset is here that supports the additional address lines to allow > 4 GiB of physical memory.

http://www.cdrinfo.com/Forum/tm.asp?m=126194&mpage=1&key=&#126194

 

[wizard]

I think far to many persons here are dismissing Merom and are not thinking about this rationally. They are getting a 20% boost at the SAME clock speed as the old chips. That is similar to 400 MHz additional performance. Granted one can not scale the MHz without other issues coming into play but still it gives you an idea about how well the chips are doing. On top of that the 64 bit option isn't likely to even be in the picture at the moment nor the other chip improvements.

What I'm getting at is that Merom is demonstrating to be a significant step forward. The real surprise is that Intel actually delivered a nice chip set.

As to the laptop chip in the iMac come on everyone here knows about the thermal issues in that machine. It is no surprise at all. What it does demonstrate clearly is that multiprocessing can deliver very usable performance at very low powers. A number of people where dismissing multiprocessing as the wave of the future a couple of years ago (I remember because I was promoting it) this should cool off those concerns for the majority of the users out there. I'm with you on power usage more manufactures need to look at this issue seriously.

The thing with Merom is that I'm seeing big upside potential performance wise. I'm surprised that more people are not up on this. Intel can accomplish this by tweaking the current process or going to the next generation feature size. Merom is nice but it still needs more effort at power reduction to scale speed.

Thanks
Dave

I think we all knew that Merom would only bring modest performance gains. I'm surprised they're as high as they are. I'm still not sure why they're using the laptop line of processors in their mid range desktop but it's certainly a testament to the power of Intel's new chips. If it keeps the iMac's cool and efficient then it's all good.

 

[Mikael]

Thanks

No problem.

the title you just mentioned belongs to the MacPro...sorry for the misunderstanding...

What a joke.

How is Winblows going on your side, Aiden? Many BSODs today?

Awww... Not this again. Windows doesn't blue screen without reason. If it did BSOD left and right, I would think that any of the three desktops at work should have gotten one in the 30,000 hours they've clocked now... I don't think I've ever seen a BSOD not being caused by bad or incorrectly configured hardware, overclocking or possibly bad drivers. As a matter of fact, the only BSODs I've had since 2002 (when I switched to XP) have been related to overclocked hardware. People need to check their damn hardware before going all ballistic over Microsoft's supposedly unstable operating system.

I always test the CPU/memory/mobo using Prime95 and Memtest86 right after I build a computer. I've caught some bad memory this way. Moreover, it has enabled me to stay BSOD-less on every machine I've built so far (that's ~15 machines in the past 5 years).

Mainly I used to leave my tower on 24/7 and the worst I would get is switching my monitor on first thing in the morning or when I got home from work and see it had rebooted itself and was telling me it was an invalid system disc.

That's almost 100% a hardware malfunction that causes Windows to restart after a serious failure. The default setting in Windows is to restart when it encounters a serious system failure and this can be disabled in the control panel to aid in seeking out the failing hardware. But I guess this is too late to fix now, since it sounds as if you sold the machine.

 

[levitynyc]

I have had a few BSODs in XP, but they are rare. Mainly I used to leave my tower on 24/7 and the worst I would get is switching my monitor on first thing in the morning or when I got home from work and see it had rebooted itself and was telling me it was an invalid system disc.

Since Mac, never once has this happened, (even though I tend to power down on this more often, I still often leave running 24/7 if it is doing something that requires up time).

Strangely enough, I am one fo the few that never had that many problems with ME.

Never had the BSOD on XP, but on ME ....WOW that was one shutty OS!

 

[DrFrankTM]

Just drop it...

He is talking about reliability data from at least the last 10 years, Aiden...data you must have no clue about, of course...after all, Macs just started doing Windows, right?

Am I the only one who's starting to find this petty crusade of yours annoying? Seriously, just drop it. The iMac is a great machine. I loved my G5 and I might well buy another iMac when I upgrade from the Mini I have now. A Mac Pro would be nice too, but we'll see. Anyways, the iMac is not the "most powerful desktop" in the world and no one gives a damn: it's an awesome machine regardless. So please, honestly, just drop it. What you said was false and still is. It's ok. Everyone makes mistakes. But drop it. It's starting to annoy me very seriously and I'd be surprised if I was the only one.

And I don't see what your personal attacks on some fine folks here are adding to the discussion. Along with opinions, AidenShaw - among others - brings a lot of technical expertise and hard facts to the table. I, for one, value that greatly, and I'm sure I'm not the only one. Indeed, the reason MacRumors is so awesome is that a fair share of the posters bring more than opinions to the forums: they also bring hard facts and educated guesses. I think that people can discuss respectfully, that people can argue respectfully, and that people can disagree respectfully. Most folks here do, and I'm sure you can do it too if you try even just a little. Thanks.

 

[AidenShaw]

Physical vs. virtual

I just assumed that being 64-bit or 32-bit was a system wide principle, either or.

A 64-bit operating system is one that provides 64-bit virtual addresses to its processes. It requires a CPU that supports 64-bit virtual addressing. The C2D is such a CPU, and runs 64-bit code and O/S.

These humongous 64-bit virtual addresses need to be translated to a physical address to reach the actual memory. The 64-bit CPU has a list of pages of physical memory, and tables to map a program's virtual address to a physical page. Once that mapping is done, the 64-bit virtual address can be used as a "synonym" for the actual physical address. The mapping is per process - two processes can use the same virtual address without interference - the same virtual address refers to different physical pages depending on the process which is using it.

In the case of the Napa(32) chipset, the chipset only has 32 address lines, and cannot physically handle more than 4 GiB of RAM. Some of those addresses are reserved for I/O purposes (such as the 256 MiB that is mapped to the VRAM of the video card).

If you plug 4 GiB of RAM into a Napa(32) system, you'll "lose" the memory that is over-mapped by I/O space. For example, right now I'm typing from a dual-Xeon (32-bit Netburst) with 4 GiB of RAM installed. Windows reports that I have 3520 MiB of memory. I've "lost" a half GiB due to these I/O space mappings. (My 4 GiB Yonah laptop reports 3.1 GiB available - PCIe systems seem to reserve a lot more memory for I/O than PCI-X systems.)

Apple is apparently saying that 3 GiB is the limit, so that they don't have to explain PCIe I/O bus mapping to people calling to complain that OSX isn't using all 4 GiB.
____________

This virtual-to-physical mapping has some other implications:

• Windows & Linux 32-bit Operating Systems can use up to 64 GiB of RAM, when running on a logic board that supports the full 36-bit addressing of the P4
• No 64-bit system has implemented 64 physical address lines. Some have implemented fewer than 32, but 36 (64 GiB) to 40 (1024 GiB) is typical (price a terabyte of RAM, and figure out how many slots you need )
• MacOS 9 and before didn't have per-process mapping tables - so if different processes used the same address, it would refer to the same physical memory. This meant a mistake by one application could make another application fail - or even the whole system.

 

[Evangelion]

The Napa chipset used with Yonah only supported 32 address lines.

Napa is the hardware-platform, composed of Yonah, Intel Mobile 945-chipset and Intel Pro Wireless. AKA third generation Centrino. And since the CPU used in that platform is 32bits, the platfom can be called a 32bit platfom. Note: this has nothing to do with the bitness of the logic-board. Napa64 (or rather: Santa Rosa) is Fourth generation Centrino that uses Merom and new chipset.

 

[wizard]

I see no reason why the new C2D iMacs can't run 64 bit code. Heck I've had a AMD 64 running Linux fro a couple of years now and it runs 64 bit code fine on 1 Gig or RAM. The 64 bit instructions are not part of the addressing scheme for the most part.

Now how well an application will run addressing more that 2 Gig of ram on these machines is another question. In part it will depend on how well virtual memory works. Performance wise it is always best to have all data in RAM, there is little doubt there, so you would not want to run large databases on a 64 bit machine with limited memory on a daily basis. It is simply a poor way to leverage the hardware. However not all 64 bit applications are data bound so one can still make serious use of the 64 bit capabilities.

The system is no more a hybrid than older machines of days pass that had 32 bit processors and could only address a small fraction of the available address space. All of the above being said though Apple is the one that writes the OS and they ultimately determine the capabilities on any one platform. I can't see them not enabling 64 bit when it is ready.

Dave

The fact that the new iMacs can't address more than 3Gb of memory and are therefore operating on a 32bit logic-board makes me doubtful as to whether or not these systems are really 64-bit capable... It seems like some kind of hybrid 32/64bit system.

Will the C2D iMacs be able to run 64bit code, despite not having the 64bit address space (and being able to access over 4Gb or RAM)?

 

[Evangelion]

In the case of the Napa(32) chipset

There is no "Napa chipset". Like I said, Napa is a hardware-platfom, composed to CPU (Yonah), chipset (Intel Express 945) and WLAN ()Intel PRO/Wireless). The amount of RAM might be limited due to timing-issues and the like.