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Where are the Large RAM Systems?
CaptCanuk asks: "I've been charged with finding a system with 16 GB of memory and have had a really hard time in acquiring one (especially with a PCIE 16x slot). Linux is at the forefront of these 'large system memory' systems and beyond beta versions of Windows XP, is the only OS that supports the 64 bit memory addressing required to use this much RAM. When I asked large beige box wholesalers, I'd get comments from 'Why do you want a 16GB harddrive...you want MEMORY? are you sure?' to 'No motherboard supports more than 4GB of memory; everyone knows that'. Where are these mythical large memory systems? Do you think such workstation configurations will become pervasive in the future? Will it take Microsoft's Windows XP 64 bit to legitimize their existence in larger quantities?"
Because if you're a company looking for reliability and ongoing maintenance, a self-build isn't necessarily the first thing you think of. You're a beancounter looking for an ongoing support contract from a reputable OEM you've heard of before, possibly with onsite or couriered-in replacement clause.
I'd like to throw out the possibility of clustering instead, though (mostly cause it's on my mind because I've been dealing with several support cases on clusters recently). Why is this not an option for extra power, resilience, etc..
Screw you all! I'm off to the pub
...there all over the place:
Dell Itanium
HP Itanium
IBM Itanium
Or, I went to AMD's page here and clicked on one of the manufacturers listed. Where I found this dual opteron supporting 16GB ram. Took me all of 2 minutes.
-- Hulver's site
http://www.appro.com/ do same damn fine boxes, including 1U (yes, 1U) quad (yes, yes, quad) operton boxes that take 32GB of RAM.
:(
I only wish the company I work for could afford boxes like that
Oh, and there's that "need" thing I keep hearing about.
That is the addressable memory space. Curiousley the x84 instruction set doesn't have a 32bit (4Gb) wall but reather an 64Gb wall due to the segment offset. This is the original hack which gave us 1Mb limit reather than the 64K.
The only reason linux gives you the choice between the two when compiling is to allow the address to be stores in one 32bit int.
Mouse powered Chips, Open source Processors and Lego
The Apple XServe supports 16Gb of RAM, the just don't like to admit it. I found this image on their site while looking for stuff last year.
Whether to use a cluster or not depends heavily on the problem domain. Until very recently, clusters didn't work so well with large databases, etc.
You also seem to be shopping specs rather than throughput. Your mention of 16x PCIexpress is what gives this away. The only cards that support this now are high, high end graphics cards, and these cards don't even need it. There's no real difference between the AGP 8x and PCIex versions of these cards.
That said, you're not going to find what you're looking for in the beige box world. You're looking (realistically) at about 4 different venders: Windows: Dell, IBM, and HP. UNIX: IBM, HP, and Sun.
You're also only looking at servers (not desktop or towers).
My experience is with Sun, and a little Dell and IBM. So I'm going to speak to those. Sun makes magnificient hardware. Their support organization has had problems recently, but the hardware is good enough that we don't need it often. Sun's V880 servers are amazing. up to 8 CPU's and up to 32 gigs of ram, with great growth potential (12 PCI slots, several of them 64 bit, 66 MHz).
We've had lots of problems with our Dell hradware. Whole lines of their servers have been crap, and dell replaced thier 16xx line with their 17xx line for us for free. Our exchange server runs on a 6550 IIRC, which has at least 8 gigs of ram. This model probably can go higher in ram, but I'm not sure.
We've been really impressed with the IBM hardware we've started to purchase. It's been pretty stable, fun to work with, etc. IBM has a long history of making great servers. They probably have several models that will help.
Zapman
OS X does not totally take advantage of more than 4GB of RAM. It can address tons of RAM, but each running application is limited to a maximum of 4GB of addressable space in Panther.
When Tiger comes out, non-gui applications will be able to address the full 64 bit address space, however, GUI apps will remain limited to the 32 bit address space. See here for more info.
Doh!
Buy an SMP opteron box, they'll support all the memory you want and then some. Most of the Opteron motherboards I've seen in use have 4 memory slots per cpu socket. So for instance with a quad opteron boards you could stick 16x 4G sticks in it for 64G of ram. Incidentally, it's not that only linux supports "64-bit addressing". The memory addressability is a function of the processor and/or memory controller (which is integrated in the processor in the case of the Opteron). There is no processor I know that can actually physically address 64 bits of memory (which would require something on the order of 65,536x 256Terabyte sticks to fill). IIRC correctly, the Opteron memory controller can physically address 40 bits of physical memory, which puts the theoretical limit for it at 1TB of RAM.
11*43+456^2
One additional thing to consider if you are planning to use Windows is the 4GB process limit (which is NOT the same as a total memory limit) in a 'normal' Windows server.
/3GB switch, bla bla bla, ....).
i d= 69
The operating system (Windows Server Enterprise Edition) will work with more than 4GB memory, but a process running on that server can only address 4GB of memory, of which 2GB is reserved kernel space (in normal circumstances, not including the
Check out:
http://www.brianmadden.com/content/content.asp?
Of course there are some tricks and things you can do, but still... keep this in mind.
This is due to the fact that you are working on 32-bit hardware that can only address 4GB directly, as far as I understand. Does Linux have this limit too? Or are there other 'tricks' that the Linux kernel applies to go above 4gb? Maybe other Slashdotters can elaborate on this.
Dell PowerEdge 6600, 6650, 7250...b oard/Xeo n800/. html
IBM xSeries 336, 346...
http://www.supermicro.com/products/mother
http://www.tyan.com/products/html/barebone
In short, every place I've checked so far.
-Uberhund
Really, I gotta wonder, what the hell are you running that requires that many pages to be in memory at the same time.
How about the entire genomic sequences of >4 organisms? That way you can compare them to each other simultaneously, and learn which sequences are similar and which are different.
Here's another application, off the top of my head: simulate the gravitational mechanics of any large system of objects. Think you want to swap that kind of thing to disk?
I submit that there are many scientific applications of this much RAM; and you're not likely to recognize or understand the need unless you're in the field yourself. A LOT of bleeding edge computing work is being driven by scientific researchers who demand, really, a heavy amount of resources to do their simulations on--and computing structures that are designed for database work/gaming is just not comparable.
Personally, we use HP quad Opterons, with 64GB of RAM each (running Linux, btw); and while you could build that kind of thing yourself, the reliability issues at that scale just aren't worth it.
--
$tar -xvf
The large system there has 4 GB RAM (4 1Gig memory sticks - substitute 8 2 GB RAM sicks gets you 16 GB memory). True, these don't have PCIe - Sun won't be getting PCIe until later this year, but the IO on this system isn't to be beatten.
If you want even more memory, try the 40z and 16 2GB RAM sticks for even more memory.
Don't expect Intel systems with Dual memory controllers to get you there - you need real systems.
I have mod points and I am not afraid to use them
Tyan just released a new series of Opteron boards that have PCIe & 16GB: They're the ones with the "E" at the end of their names [e.g. Thunder K8WE -vs- the older Thunder K8W].