Parallels or VMware Fusion?

[bbloke]

Originally Posted by chevy

This is the good part of macosx.com... people have opinions and preferences.

Absolutely, I agree.

It's good to have a range of people from different backgrounds and with different experiences. I certainly was not criticizing earlier, by the way. We all have our preferred tools for each task, and it is good/useful to hear why people make the choices they do.

Originally Posted by chevy

Fryke likes Parallels, giaguara is keener on VMWare. So you see both sides... and then it's up to you to decide.

Argh, that's the problem... I'm not so good at making decisions!

[Giaguara]

If you plan on using end applications that are compiled for 64-bit, then running them on 64-bit OS will be more smooth.
("4) Use a 64-bit virtual machine with a 64-bit OS, if you have one available." Link)
Windows performance 32 vs 64
"The better performance with x64 OSes is only with x64 apps like autocad 2008, 32-bit apps run as usual." on AutoCAD.
Ubuntu: 32 or 64bits? Does it make a difference in Fusion? link
Would 64-bit be advantageous in a VM? link
Everything posted before early August 2007 in these links here refer to beta version, 50460. So with official release there should be even smoother performance.

If you need VMI paravirtualization or plan to run only 32-bit compiled applications, then it may be ok to stick to 32-bit OS. For now.

I guess one could find some 64-bit compiled audio, video or graphic editing software suite that uses resources, and measure the differences in the same tasks running it on 32-bit VM and on a 64-bit. Or just have a business need for a 64-bit ...

[fryke]

*cough* ... I still - after all these years of Apple promoting 64bit computing (remember the G5?) - haven't heard whether 64bit computing makes any sense *at all* on a computer with less memory than the bottleneck size of 32bit memory addressing. Maybe my _question_ is stupid, could very well be. But if 64bit mainly is about using stuff that can address RAM in excess of 4 GB, then what good does a 64bit virtual machine with, say, 640 MB RAM do on a machine with 1 or 2 GB of RAM do?

As I understand it (and I probably don't), in these "low" memory circumstances, 64bit will only add overhead and solve nothing, really. This is not a rant against vmware, btw., I wish Parallels would also support 64bit OSs, clearly. (And I hope BootCamp will out of the box, some day, as well.) But this thread is about an iMac with memory constrictions (up to 4 GB of RAM).

[fryke]

Okay. Wikipedia to the rescue... (maybe...):

A common misconception is that 64-bit architectures are no better than 32-bit architectures unless the computer has more than 4 GiB of memory. This is not entirely true:
Some operating systems reserve portions of process address space for OS use, effectively reducing the total address space available for mapping memory for user programs. For instance, Windows XP DLLs and userland OS components are mapped into each process's address space, leaving only 2 to 3.8 GB (depending on the settings) address space available, even if the computer has 4 GiB of RAM. This restriction is not present in 64-bit Windows.
Memory mapping of files is becoming less useful with 32-bit architectures, especially with the introduction of relatively cheap recordable DVD technology. A 4 GiB file is no longer uncommon, and such large files cannot be memory mapped easily to 32-bit architectures; only a region of the file can be mapped into the address space, and to access such a file by memory mapping, those regions will have to be mapped into and out of the address space as needed. This is an issue, as memory mapping remains one of the most efficient disk-to-memory methods, when properly implemented by the OS.
There may be other incidental advantages as a result of the transition - for example, in the case of x86-64 compared to x86, twice as many registers are available for programmer use.
The main disadvantage of 64-bit architectures is that relative to 32-bit architectures the same data occupies slightly more space in memory (due to swollen pointers and possibly other types and alignment padding). This increases the memory requirements of a given process and can have implications for efficient processor cache utilization. Maintaining a partial 32-bit model is one way to handle this and is in general reasonably effective. In fact, the highly performance-oriented z/OS operating system takes this approach currently, requiring program code to reside in any number of 32-bit address spaces while data objects can (optionally) reside in 64-bit regions.

So it seems that _theoretically_ it could help with a computer with 4 GB of RAM, but I guess at anything lower, it simply shouldn't make much of a difference.

[Mikuro]

Memory addressing is not the only factor. Actual processing power is greater, too. A 64-bit chip can operate on larger data types (e.g., 64-bit integers) much more efficiently. You can use these data types on 32-bit chips, of course, but what goes on under the hood is different, and much more expensive.

As for whether this actually matters to most people....probably not, at least for now. 64-bit apps are rare, and most apps would probably not benefit greatly anyway.

I imagine scientific apps run significantly faster on 64-bit chips (I know Mathematica is optimized for 64-bit processors), and there is certainly potential in graphics and multimedia, as well. Real-world comparisons of equivalent 64-bit and 32-bit software on the same hardware are hard to come by, though.

On the other hand, even the G4 had AltiVec, which provides some of the advantages of 64-bit (and even 128-bit) processors, which could diminish the advantages of a "true" 64-bit processor. I'm not sure if the G5's AltiVec enhancements had anything to do with its 64-bit-ness.

[bbloke]

With regards to 64-bit computing, I found three articles that may be of interest, although they may not directly answer your questions.

Geek Patrol has an article on 32-bit vs. 64-bit performance in the Mac world.

Originally Posted by Geek Patrol

• Mac Pro
  • Intel Xeon 5150 @ 2.66GHz
  • 2048MB RAM
  • Mac OS X 10.4.7 (Build 8K1124)
  • Geekbench 2006 (Build 208)
• iMac (Late 2006)
  • Intel Core 2 Duo @ 2.0GHz
  • 1024MB RAM
  • Mac OS X 10.4.7 (Build 8K1106)
  • Geekbench 2006 (Build 208)
• Power Mac G5
  • PowerPC G5 @ 2.0GHz (two processors)
  • 1024MB RAM
  • Mac OS X 10.4.7 (Build 8J135)
  • Geekbench 2006 (Build 208)

Originally Posted by Geek Patrol

Mac Pro Summary
Overall performance in 64-bit mode is 5% higher than overall performance in 32-bit mode. However, a number of benchmarks that were slower in 64-bit mode than in 32-bit mode (like the Blowfish and Write Sequential benchmarks).

...
iMac Summary
Despite the fact that the Core 2 Duo and the Xeon share the same underlying architecture, the Core 2 Duo’s 64-bit performance is better than the Xeon’s 64-bit performance; overall performance for the Core 2 Duo is up 7% (compared to 5% for the Xeon). Plus, the only benchmark that was significantly slower in 64-bit mode was the Blowfish benchmark.

...
Power Mac Summary
Overall performance is down 10% in 64-bit mode. Hardly any tests are appreciably faster in 64-bit mode, and several are noticeably slower (such as most of the integer tests, as well as the dot product test).

...
It turns out the assertion that software runs faster in 64-bit mode than 32-bit mode is both correct and incorrect; Geekbench runs faster in 64-bit mode on Intel-based Macs, but slower on PowerPC-based Macs. I find this incredibly surprising.

Also, there is an article on Ars Technica, although a few years old, which discusses the state of 64-bit computing... back then. In another article, Ars Technica talks about 64-bit computing with Leopard, and Apple's possible decision to not include 64-bit support in Carbon.


Back to virtualization, has anyone out there tried both VMware Fusion and Parallels Desktop, in their current forms, and been able to make their own comparison? I'm currently contemplating buying Fusion or Desktop, but am unsure of which to go for. I was originally going to go with Desktop, perhaps by default, but have been hearing good things about Fusion recently. It's a tough call, but my thoughts are also that VMware has a good history in the field and they've only just started with Fusion... I may be leaning towards Fusion now, but am undecided!

[fryke]

I think both can be tested. Why not install the same OS(s) in both solutions and make some initial testing before deciding? Before doing so, make a checklist of what you'd be doing on a regular basis with the system(s). Then, when testing, note what surprises you (positively and negatively). This way, you could write the perfect review for _you_. (And tell us, of course.)

[Giaguara]

Why not test both indeed. Both have a free 30 days version for testing working fully with the OS, applications and appliances you need, and once you have made up your mind, pick the one you want.