will 64bit OS speed up render times?

[twine]

Hi, im new to lightwave, and was wondering if it is worth me installing the new windows xp 64 bit operating system in an attempt to speed up render times for lightwave?

[Mylenium]

Hi, im new to lightwave, and was wondering if it is worth me installing the new windows xp 64 bit operating system in an attempt to speed up render times for lightwave?

Unless you happen to have a true 64 bit processor and access to the 64 bit version of LW, it's not going to do anything. Actually installing a 32 bit app on a 64 bit system is even going to slow things down.

Mylenium

[Captain Obvious]

I would like to state this in very big letters so there is no confusion on the matter:

A 64-bit system (including software, OS, processor, everything) WILL NOT speed up rendering in Lightwave, or most other 3D renderers, at all.

The benefit is that you can have scenes of a complexity that were previously impossible. A scene the old Lightwave could handle will not be faster in a 64-bit Lightwave. A scene the old Lightwave couldn't handle will, on the other hand, be easy for a 64-bit Lighwave. Easy but slow.

Why is this? Well, essentially, it's because Lightwave (and most other renderers) use floating point numbers for almost all render calculations. Almost all CPUs since the Pentium and original PowerPC (and probably earlier) have been able to do 64-bit floating point calculations. A few renderers, like POV-ray, use 64-bit integers, and will obviously be a lot faster with a 64-bit system, but Lightwave (and Fprime, and probably Kray, mental ray, Maxwell, Brazil, etc) use floating point numbers.



Unless you happen to have a true 64 bit processor and access to the 64 bit version of LW, it's not going to do anything. Actually installing a 32 bit app on a 64 bit system is even going to slow things down.
This is incorrect. In Windows XP-64, Mac OS X and all other hybrid 32/64-bit OSes, a 32-bit application will run at the same exact speed as it would in a 32-bit environment. Thusly, unless a 64-bit counterpart would be faster, there is no real difference. A 64-bit Firefox will probably not be faster than a 32-bit, regardless of whether you run it in a 32-bit or a 64-bit environment. Unless of course it's an only 64-bit environment, like Alpha, but that's a different matter.

[Travolta]

I suppose it will be faster in some cases when 64 bit coluculations eliminates need of few passes and everything can be done in one pass. Also I`m agree that on 64 bit enviroment 32 bit applications will run slower - in theory at least - because when AMD64 runs in 64 bit mode the only way to run 32 bit applications is to emulate 32bit mode (x86) on software level. In WinXP 64bit there is a x86.dll to do this job. Unlike Mac architecture there is another system on PC - CPU can work only in one mode -32 or 64 and its impossible to swap "on fly" !

[hrgiger]

It's like the age-old question will more memory speed up rendering. The simple answer is no.

Unless your processor has to access virtual memory. Which is basically the only way that the 64 bit platform will keep things zipping along, provided you have enough memory of course.

[Captain Obvious]

because when AMD64 runs in 64 bit mode the only way to run 32 bit applications is to emulate 32bit mode (x86) on software level
AMD64 is fully backwards compatible. 32-bit code runs just as fast on a 64-bit Athlon64 as it does on a Sempron, when the only difference between the two is that the latter is 32-bit only. Just like the G5.

[twine]

Quote:

AMD64 is fully backwards compatible. 32-bit code runs just as fast on a 64-bit Athlon64 as it does on a Sempron, when the only difference between the two is that the latter is 32-bit only. Just like the G5.

Glad to hear it.

I do have an AMD64 proccessor, its a 3400+, and I was thinking of installing the demo version of the new 64bit os from M$.
I do know someone that has already installed it (he doesnt use LW) and he says there is no noticable difference. Obviously the fact that there is not much in the way of 64 bit programmes out there yet is the main reason for this.
But I would be very dissapointed and surprised if 32bit programmes ran slower with the new 64bit os.

Quote:

The benefit is that you can have scenes of a complexity that were previously impossible. A scene the old Lightwave could handle will not be faster in a 64-bit Lightwave. A scene the old Lightwave couldn't handle will, on the other hand, be easy for a 64-bit Lighwave. Easy but slow.

So, I would consider this to be a good enough reason to install the 64bit OS. Anyone have anymore info on this particular advantage?

All your comments have been helpful, and this is a topic that i am sure everyone will need to learn about more in the near future.

[Lynx3d]

AMD64 is fully backwards compatible. 32-bit code runs just as fast on a 64-bit Athlon64 as it does on a Sempron, when the only difference between the two is that the latter is 32-bit only. Just like the G5.

Travolta is still correct, XP x64 runs 32bit applications through a translation layer called "WOW64" (Windows on Windows64), which translates all system calls.
That means, there IS a slight overhead when running 32bin applications in Win64, but since the rest of the system is exclusively 64bit (including all drivers!), 32bit applications actually "use" 64bit drivers, so the overhead can sometimes even turn into a slight advantage (in case you forgot, 64bit long mode has more CPU registers available, hence compiler often can, in contrast to PPC, create faster binaries, though in most cases not dramatically faster)
But with rendering i would expect pretty identical speed until you can get hold of 64bit Lightwave, and even then don't expect miracles...

On a side note, 32bit applications can use up to 4GB memory on XP64, but ONLY if they set "IMAGE_FILE_LARGE_ADDRESS_AWARE", which basically means applications that already could use more than 2GB in 32bit Windows, i.e. up to 3GB with /3GB boot switch enabled in XP.

[Captain Obvious]

Travolta is still correct, XP x64 runs 32bit applications through a translation layer called "WOW64" (Windows on Windows64), which translates all system calls.
I didn't know that. Well, it's still a feature of XP-64, not 64-bit OSes, as such.

[mattclary]

That's nothing new, it's the same way 16bit apps run on NT through XP. I'll never switch back to a 16bit processor because of this. :rolleyes: