I'm trying to get a feel for how you guys think home PC's are going, do you think in a year it will be common to see "off the shelf" PCs with 6 or 8 GB of RAM, or will it still be a rarity. Right now, it seems that 4GB is the typical max available, i.e. on Dell.com until you go to the "Big Business Servers" or whatever it still seems like their configs top out at 4GB.

I'm just wondering because I'm working on the latest-generation MetOffice climate model for CPDN (hadgam/hadgem). At the higher resolution (still lower than the Seasonal Attribution Expt but that is an old model), it likes to use 4.7GB of RAM! If we drop it to "usual" CPDN resolution of 96x73 (although with twice (38 vertical levels), it runs about 1.5-2GB, which is more manageable for today's higher end machines.

Of course the scientists want to keep the higher (192x145x38) resolution, but I'm wondering if even in a year we'd have 10 participants with machines that don't mind doing a job that uses 5GB of RAM, 2GB of disk space, 200MB uploads, 100MB downloads, etc!

PS -- In looking through the CPDN BOINC database of machine specs, it looks like there's only been about 1000 machines with > 4GB; out of a global / "ever tried CPDN" pool of 200K. So right now it still seems to be very uncommon; I guess just for specialist geeks etc.

I can't speak to future trends at all. But I'm somewhat familiar with the current market as I just bought a new laptop.

The one I bought has 2 GB of RAM. It's not a particularly high end machine (I'm still debating whether it's a Pentium M dual core as the box says or a Core Duo (Yonah) as CPU-Z says). The laptops still seem to be pretty evenly split between having 512 MB and 1 GB of RAM (I wouldn't touch Vista on 512 MB - XP is painful enough with that amount). One of the reasons I decided on the one I bought was the amount of RAM it came with. I took that over a slightly faster processor because of all I had read about Vista being a memory hog. It was one of the few laptops I did see that had 2 GB of RAM. Even the higher end ones are coming with 1 GB.

It's been a couple months since I looked at desktops but they seemed to be trending towards 1 GB of RAM. But there is still a fair number of machines coming with only 512 MB of RAM.


RAM is getting pretty inexpensive. About 9 months ago, I bought 2 x 512 MB at Circuit City for about 75 dollars after rebates.

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Kathryn :o)

Kathryn wrote:

RAM is getting pretty inexpensive. About 9 months ago, I bought 2 x 512 MB at Circuit City for about 75 dollars after rebates.

I just saw a discussion on slashdot saying that memory manufacturers had anticipated a large demand for memory when Vista was released. But Vista adoption has been sluggish, so there's now lots of memory and the price has dropped as a result.

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-- Eric Myers

"Education is not the filling of a pail, but the lighting of a fire." -- William Butler Yeats

I recently read an article that said ordinary computer users would hardly see any improvement in performance by buying more than 3Gb.

When I ordered the parts for my new computer a few months ago, I was surprised at how inexpensive the motherboard and hard drive seemed. But the 2Gb of RAM cost quite a lot. If I'd chosen 667 the two cards would have cost about £160 in the UK, and the faster 800 I bought cost over £200 which is rather a lot. So 1Gb per core for 4 or more cores is probably something that most non-boincers would consider both superfluous and crazy.

One problem I foresee for people running long WUs like cpdn models on 4 or 8-core machines is backups and restores after a model crash. At the moment the only practical way non-gurus can restore the backup of a crashed model is to restore together ALL the models running on that machine. So to save one crashed model, it could be necessary to make 3 or 7 good models repeat some crunching time. We'd need to get our act together and start recommending frequent auto-backups as standard practice.

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Kathryn set up a Trac item requesting a backup feature in April which I've been keeping an eye on:

http://boinc.berkeley.edu/trac/ticket/39

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Currently I don't see any mention of multithreaded work unit scheduling in any /Trac items, but this should really be considered as an option over the next year or two. Whle I don't know if multithreading is an option for Carl's model or not, it's a good example of the sort of work unit which would benefit.

A giant work unit (5GB) such as being discussed here would likely run on a PC with many cores (server or very-high-end enthusiast's machine), but a max of 1 or 2GB RAM per core (since core-count is rising quicker than memory). If it was running with a single thread, it would be RAM-bound and most of the CPUs would be idle. On the other hand, if it were allowed to use all available cores for one work unit then it'd run much quicker (i.e., on an 8GB box with 4 cores, you could run one model using one core, and have smaller jobs on the other cores, or run the same model using all the cores in ~1/4 the time).

The work-request process might need to consider memory size (i.e., don't simultaneously issue 4 5GB work units to a PC with 8GB and 4 cores since only one can practically run at a time).

The round-robin simulator would also need to take this into account. In addition it'd need to be able to simulate a task taking up many cores rather than assuming each task is one core.

The daemon would need to only start sufficient tasks to use the PC's core count (e.g., 2 tasks with one thread, 1 with 2 threads). On the other hand, if a work unit is not keeping all it's threads busy 100% of the time, perhaps a few extra running tasks would be OK as long as CPU starvation doesn't occur.

Will Boinc's different components be able to cope with this within the next few major releases (6.x, 7.x)?

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sending out multicore-ready models (via MPI) is something I've been toying with, esp for the higher-res models. although I'm not sure how BOINC will react to that, I suppose it couldn't stop our monitor job from launching a 2 or 4-CPU-usage model, but it would probably schedule other work to be done on these CPUs so we'd all be "fighting" for the same cores etc.

as a recap of the high-memory/res model I'm talking about -- at the 192 longitude x 145 latitude x 38 vertical levels (N96) resolution it seems to be using 4.7GB of RAM peak, typically at 4.5GB. It does a timestep (30 minutes of simulated time) in about 2 minutes! This is on a box that would do a normal 32-bit CPDN model (i.e. hadcm3) at a timestep in 2 seconds. So technically, this is what you would call a "doozy!" ;-)

the "normal" res version of this model (hadgam1a at 96 long x 73 lat x 38 vert levels) is quite a bit friendly -- running at 1.2GB peak RAM usage, 1GB typical, and a timestep every 15 seconds. All of these models are running at 64-bit maths (-i8 -r8) by the way -- and these numbers are for 64-bit machines & OS's (you can run -i8 -r8 on a 32-bit box/OS of course, and we probably will make versions for that; but the timings will be longer). We won't do 40 or 80 or 160 year runs with these models of course! It will be more like the Seasonal Attribution Project -- i.e. 6 months or a year or maybe two years simulated.

we can do a lot of science with the N48 ("normal") res version; although our proposal was really for the N96, so hopefully we can get at least about 1000 with big memory upgrades that don't mind using almost 5GB for CPDN! I guess we'll offer "extra credit" for that! ;-)

One thing I would like to point out is that many new machines are still only putting 2 DDR2 module slots on the MB and don't take more than 1GB ram per slot so they are limited to 2 GB ram total.

Too many of the consumer machines, even with Vista Home Premium, are still using the i945G chipset and only putting 2 RAM slots to save manufacturing costs. It's really annoying.

-- David

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David Ball

The new P35 low-end chipset should help that, will take a while to reach the market in quantity of course.

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The new P35 low-end chipset should help that, will take a while to reach the market in quantity of course.

I've heard some good things about that chipset. IIRC, someone tested it against the 965 chipset and it was faster with the same CPU and RAM due to some improvements in the memory controller.

-- David

The one I bought has 2 GB of RAM. It's not a particularly high end machine (I'm still debating whether it's a Pentium M dual core as the box says or a Core Duo (Yonah) as CPU-Z says).

"Pentium M dual core" is another example of intel's confusing branding system. It's a yonah with only 1 of the 2 1mb banks of cache enabled. I assume it's like the late 90's cacheless celerons that started out as a way to dump what would otherwise be QC rejects onto the market at the very low end.

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[img] http://boincstats.com/signature/-1/user/926/sig.png[/img]

The one I bought has 2 GB of RAM. It's not a particularly high end machine (I'm still debating whether it's a Pentium M dual core as the box says or a Core Duo (Yonah) as CPU-Z says).

"Pentium M dual core" is another example of intel's confusing branding system. It's a yonah with only 1 of the 2 1mb banks of cache enabled. I assume it's like the late 90's cacheless celerons that started out as a way to dump what would otherwise be QC rejects onto the market at the very low end.

Thanks for the explanation.

I've actually been quite happy with it. It sure beats the hot, noisy P4 laptop that sits on top of my bookcase and just crunches.

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Kathryn :o)

Well actually many machines who are being updated with 4 Gb of memory seem to have a problem because somehow the os does not see or report the right amount of memory (windows xp,vista and seems even 2003 has this problem).
It seems that these machines only report 3 Gb of memory and are not addressing the extra 1 Gb memory.

On the other hand am i and some of my hardcore cruncher buddies are waiting till the new amd barcelona cores are released and if satisfied about the performance we'll buy a 2 cpu 8 core box with about 4 or 8 Gb of ram.

In stead of running 4 machines like i do now i will have one big machine with
loads of cpu's and memory :D

On the other hand we are cautious because we are not sure if these machines get support from os/program manufacturers anytime soon.

But at the moment it probably is going to be either linux or a win 64 os depending if these won't have a problem with the 3 Gb barrier.

I could install 4 Gb of mem on this machine, but when i do i have to lower the timings because of stability with more memory modules
I have these DDR running at 2-2-2-5 at 1T, i think many users gets issues with the stability if using 4 modules.

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There's a good article about the 3GB memory limit issue here:

http://www.dansdata.com/askdan00015.htm

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Well my notebook computer just crashed and I had to buy a "cheap" replacement this week. It was a Toshiba with 17 inch monitor, all the bells and whistles, and 3 gigs of ram. That was only $699. I was pretty shocked it came with that much ram. It seems to me if a "cheap" laptop gives you that much the high level desktops should be offering at least 5 gigs of ram right now. I didn't look at them but I would bet they do.

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Well actually many machines who are being updated with 4 Gb of memory seem to have a problem because somehow the os does not see or report the right amount of memory (windows xp,vista and seems even 2003 has this problem).
It seems that these machines only report 3 Gb of memory and are not addressing the extra 1 Gb memory.

That's a deficiency of the *architecture*, not of those operating systems. *Any* 32-bit operating system will be unable to address the whole 4GB of memory.

32-bit can only address 4GB of virtual memory, it needs some of that to talk to hardware devices and other purpose, and then there is the swap space. There is no way it can leave the whole 4GB address space available for physical memory.

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