IBM is very far along developing optical interconnects for chips that are as fast or faster than todays copper interconnects... So picture this..
Say your processor has 4 optical connectors that connect to optical switches... you buy pure cache modules that interconnect via that same optical system.. Adding another switch allows you to stack and stack and stack.. Think about a 8 core chip that can interconnect with up to 16 * 32MB L2 or L3 cache modules...
Or you keep plugging more 8 core chips, and more 8,12,16,32MB cache modules into the clustered CPUs...
IMO, this is one of the directions IBM is going to take the POWER line.. and hopefully even the CELL B.E.
Please be so kind to test Your new modifications in Opera as the new movong add is not possible to close (no close button) and renders across the published conetnt in the middle of the screen.
Also, login to post comments stopped working..
Sorry to post here, dop not have account on forums.
"Remember that currently all 32 bit OS make use of 4 KB size, but that most 64 bit OS (Linux and windows) can use 4 KB or 2MB page size."
That's actually quite false. 32-bit OSes have been able to use hugepages (>= 2MB page size) for many years. I'm relatively sure that ability was added along with PAE to the P6 core, ala PentiumPros back in the day. Linux itself has had hugepage support since the 2.0.x kernel series. I've used hugepages for Oracle databases in Oracle databases for at least 5-years now.
Now granted you get more benefit from larger memory footprints which 64-bit CPUs give you access too, that doesn't mean you can't use hugepages in 32-bit environments. There's 64-bit requirement.
What I'm really waiting on are x86 supporting page sizes > 2MB. Itanium does up to 256MB pages I believe, and Alphas long ago support 64MB pages. I'm deploying SunFire x4600s with 8GB of RAM per core, and hugepages is an ENORMOUS performance benefit.
A key point that you're missing about the differences in 32 and 64 bit computing is that despite the fact that *some* OSes have used PAE, it does so with a performance hit, potential problems with drivers, etc. In the case where software such as what Adobe pumps out, the total number of pages that can be open cannot exceed 2GB. With 64 bit computing, you can have numerous pages open each of which consume a maximum of 2GB. So, you could easily have three pages open each consuming 2GB for a total of 6GB on your system. You couldn't do the same with 32 bit without using PAE.
Furthermore, with PAE, no single application could use more than 4GB of RAM. AWE allowed applications to exceed 4GB, but not simultaneously.
64 bit is the way to go if you're going past 3-4GB of RAM. It's a shame that MS created a 32 bit Vista.
...and practically, although you limit memory hungry processes to 4GB (well, half that is normally reserved by the kernel, so it is actually 2GB), your cache manager can still make use of the rest. Adobe advocates using systems with more memory than 4GB, since file I/O is improved (Photoshop enables caching for their swap-files in case the user has lots of memory).
That said, I fully agree that 64-bit is where it is happening. We've pushed the 32-bit design to the limit and it is time for everyone to move on...
oh, I forgot to say that I realize XPSP2 is still limited to a 32-bit address space, despite toggling PAE support on. (and I'm fully aware that 32-bit drivers from manufacturers like nVidia does not support the extended memory address space -- I have to limit 32-bit Windows server 2003 to 32-bit addresses if I want to play well with the nVidia drivers)
The Itanium supports up to 4GB pages (and a lot of other sizes
between this and 4k).
What *I* would like to see is support for various pages sizes at runtime. Larger sizes for e.g. DMA buffers, hugepages for database folks, and small pages for everything else.
IIRC most processors can only support ONE (selectable) pagesize at
runtime.
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15 Comments
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mvrx - Friday, April 4, 2008 - link
IBM is very far along developing optical interconnects for chips that are as fast or faster than todays copper interconnects... So picture this..Say your processor has 4 optical connectors that connect to optical switches... you buy pure cache modules that interconnect via that same optical system.. Adding another switch allows you to stack and stack and stack.. Think about a 8 core chip that can interconnect with up to 16 * 32MB L2 or L3 cache modules...
Or you keep plugging more 8 core chips, and more 8,12,16,32MB cache modules into the clustered CPUs...
IMO, this is one of the directions IBM is going to take the POWER line.. and hopefully even the CELL B.E.
mino - Monday, March 31, 2008 - link
Please be so kind to test Your new modifications in Opera as the new movong add is not possible to close (no close button) and renders across the published conetnt in the middle of the screen.Also, login to post comments stopped working..
Sorry to post here, dop not have account on forums.
Visual - Monday, March 31, 2008 - link
seconded, i get a nasty floating thingy that i can not close, and i am with firefox+noscript (anandtech.com scripts allowed, all the others blocked)chiadog - Monday, March 31, 2008 - link
Thanks for removing the Ad. Not only was it annoying and intrusive, it wasn't very relevant either. Why do we need to know about Shanghai the city?thesix - Saturday, March 29, 2008 - link
Barcelona is a city name, so is Shanghai (one of the best cities in China). What is 'Shangai'?Nehemoth - Sunday, March 30, 2008 - link
Well as Barcelona is an Spanish city, Shangai is how you write in Spanish Shanghai.:- )
JohanAnandtech - Sunday, March 30, 2008 - link
Shangai was nothing more than a typo... FixedThaHeretic - Thursday, March 27, 2008 - link
"Remember that currently all 32 bit OS make use of 4 KB size, but that most 64 bit OS (Linux and windows) can use 4 KB or 2MB page size."That's actually quite false. 32-bit OSes have been able to use hugepages (>= 2MB page size) for many years. I'm relatively sure that ability was added along with PAE to the P6 core, ala PentiumPros back in the day. Linux itself has had hugepage support since the 2.0.x kernel series. I've used hugepages for Oracle databases in Oracle databases for at least 5-years now.
Now granted you get more benefit from larger memory footprints which 64-bit CPUs give you access too, that doesn't mean you can't use hugepages in 32-bit environments. There's 64-bit requirement.
What I'm really waiting on are x86 supporting page sizes > 2MB. Itanium does up to 256MB pages I believe, and Alphas long ago support 64MB pages. I'm deploying SunFire x4600s with 8GB of RAM per core, and hugepages is an ENORMOUS performance benefit.
wordsworm - Sunday, March 30, 2008 - link
A key point that you're missing about the differences in 32 and 64 bit computing is that despite the fact that *some* OSes have used PAE, it does so with a performance hit, potential problems with drivers, etc. In the case where software such as what Adobe pumps out, the total number of pages that can be open cannot exceed 2GB. With 64 bit computing, you can have numerous pages open each of which consume a maximum of 2GB. So, you could easily have three pages open each consuming 2GB for a total of 6GB on your system. You couldn't do the same with 32 bit without using PAE.Furthermore, with PAE, no single application could use more than 4GB of RAM. AWE allowed applications to exceed 4GB, but not simultaneously.
64 bit is the way to go if you're going past 3-4GB of RAM. It's a shame that MS created a 32 bit Vista.
BikeDude - Sunday, April 6, 2008 - link
32-bit XP has PAE enabled by default by SP2....and practically, although you limit memory hungry processes to 4GB (well, half that is normally reserved by the kernel, so it is actually 2GB), your cache manager can still make use of the rest. Adobe advocates using systems with more memory than 4GB, since file I/O is improved (Photoshop enables caching for their swap-files in case the user has lots of memory).
That said, I fully agree that 64-bit is where it is happening. We've pushed the 32-bit design to the limit and it is time for everyone to move on...
BikeDude - Sunday, April 6, 2008 - link
oh, I forgot to say that I realize XPSP2 is still limited to a 32-bit address space, despite toggling PAE support on. (and I'm fully aware that 32-bit drivers from manufacturers like nVidia does not support the extended memory address space -- I have to limit 32-bit Windows server 2003 to 32-bit addresses if I want to play well with the nVidia drivers)mlau - Saturday, March 29, 2008 - link
The Itanium supports up to 4GB pages (and a lot of other sizesbetween this and 4k).
What *I* would like to see is support for various pages sizes at runtime. Larger sizes for e.g. DMA buffers, hugepages for database folks, and small pages for everything else.
IIRC most processors can only support ONE (selectable) pagesize at
runtime.
pm - Monday, March 31, 2008 - link
Most processors can only support one selectable page size. But the Itanium does support multiple page sizes while running:http://www.gelato.unsw.edu.au/IA64wiki/Ia64SuperPa...">http://www.gelato.unsw.edu.au/IA64wiki/Ia64SuperPa...
johnsonx - Friday, March 28, 2008 - link
yes, but how many fps do those things get in Crysis?ThaHeretic - Thursday, March 27, 2008 - link
There's [no] 64-bit requirement. (sic)