4Gb > 8Gb improvements and pitfalls ?

The recent Intel supports PAE, allowing to address more than the theorical 4GB. But somehow PAE is not supported by windoze operating systems. Works great in Linux and OSX, where the OS can use the 8GB easily, at slices of 2GB per process of course. Still, I can run photoshop 32 bits in OSX and tell it to use 4GB of cache ram, it works just fine.

With PAE, I see little point of using a full blown 64 bit OS -- there is a ridiculously small number of applications that needs more than 2GB address space, and those that /do/ mostly have an abstraction layer to handle the case (ie Photoshop). For the 99% of rest of the applications, it's not needed, and it's a massive waste to have 64 bits pointers.
 
BusError said:
The recent Intel supports PAE, allowing to address more than the theorical 4GB. But somehow PAE is not supported by windoze operating systems. Works great in Linux and OSX, where the OS can use the 8GB easily, at slices of 2GB per process of course. Still, I can run photoshop 32 bits in OSX and tell it to use 4GB of cache ram, it works just fine.

With PAE, I see little point of using a full blown 64 bit OS -- there is a ridiculously small number of applications that needs more than 2GB address space, and those that /do/ mostly have an abstraction layer to handle the case (ie Photoshop). For the 99% of rest of the applications, it's not needed, and it's a massive waste to have 64 bits pointers.
Click to expand...

You do have some benefits for speed.
1) more registers
2) pointers can be passed by register rather than stack loaded
3) no address translation
4) wider integer registers


You are right - there are a lot of applications that can use caching rather than use >4GB of ram.
Infact OSX actually has, as part of it's frameworks, classes that support caching so 32bit apps can use them and utilise additional memory as the cache (the OS running 64 or resolving the 32bit limits). It's funny - Apple tout that Leopard is 64bit. It is (ish) but they do raise the point- do you really need to produce a 64 bit application rather than cache? Often the 32bit is faster because of the smaller sizes - especially as the OSes nowdays support them well with >4GB data.

Where it fails is where you have large data sets for processing (I don't mean image or streamed). Medial CAT scan data or data for visualisation (such as VTK) utilise large amounts of RAM and going to disc is an option but you can't wait too long for data for medical diagnosis!
In this situation we're looking at 16 or 32GB of ram in the workstation purely for the datasets.

People forget that they think that all applications will suit every user of the technology. Intel and others will actively market 64bit as the next best thing because the additional pick up pays for the R&D and they don't have to push the total cost onto the small number of users that will actually make use of large amounts of memory.
 
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Some speciality programs benefit hugely from 64-bit. I doubt there are many computer chess freaks here, but the top chess engine in the world, called Rybka, has a 64-bit and a 32-bit exe. The 64-bit exe searches about 70% faster (seventy percent) than the 32-bit exe. That's enormous. It's coding style and techniques are optimised for 64-bit, and when it is compiled for 32-bit, the speed loss is very evident indeed.
 
i went from 4 -> 8gb about 6 weeks ago and to be perfectly honest Vista does run a lot more fluently with the 8gb under the hood....it's not an amazing difference but i wouldn't go back to 4gb unless i had to - put it that way.

and now in linux i can load up multiple VM's for testing w/out worrying about memory limits - vista/xp/freebsd/gentoo running under Arch Linux in a VM = :p
 
I'm about to go to 8GB, currently on 4GB. Vista isn't as smooth as I expected on 4GB, lots of disk activity. Maybe that is just superfetch at work, or maybe it is just Vista. I'll see what improvement I get
 
You think i should go from 2gb to 8gb if im going to move from xp 32bit to vista 64bit?

Last time i upgraded, 2gig was the daddy, seems odd that a lot of people on here are saying 8gigs is now better :eek:

I take it most of you are getting your 8gigs via 4x2gig sticks?
 
day to day stuff u dont notice stuff i got my new right quad core cpu 8gb of ram and stupid other stuff doing stuff like internet and itunes my laptop with half this spec is just as good but when i do video work i can see the difference and its always nice to know can run just about anything coming out for a while
 
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