I'm running BOINC on a Mac Pro (4x2.6 Ghz, 1 GB RAM) and I'm thinking of adding another gig. What effect, if any, is this going to have on either RAC or system performance with BOINC running?

Thanks in advance.

---

Unless you are running Rosetta and Ralph/WCG and/or several other projects with 'Keep in Memory' set on, it shouldn't make much difference. Rosetta, Ralph and WCG all have large memory requirements (I've seen WCG get up to 400MB working set!).

You could check out your current situation by running Process Explorer by Sysinternals. Execute it while you are running a heavy load and check the memory requirements and commit charge. The Help is pretty good but, as a rough rule of thumb, if commit charge is getting above 50% regularly you could probably benefit from the extra memory.

I'm assuming that you are running under Windoze, if not I just wasted five minutes writing this as I haven't a clue how to check it out under any other OS.

---

No Windows here. Mine is a Mac with OS 10.4.8.

My thinking is that with computer's 4 processors sharing only 1 gig of memory, each will have only 256 megs which doesn't seems like a lot. I'm only running Rosetta and it doesn't stay in memory so I'm not too worried about performance on other tasks but my wife still thinks the computer is "slow". What she's talking about is how fast web sites load since that's mostly what she uses our computer for. I think this is mostly a function of the connection. However, there is sometimes a slight delay while BOINC makes room in the memory and I'd like to avoid this since it actually is pretty annoying. with more ram I thought I could make it resident in memory and keep it running all the time, makiing us both happier.

And by the way, please feel free to correct me if I'm wrong about any of the technical stuff I've said.

---

I'm running BOINC on a Mac Pro (4x2.6 Ghz, 1 GB RAM) and I'm thinking of adding another gig. What effect, if any, is this going to have on either RAC or system performance with BOINC running?

For Xeon systems (including Mac Pro), you need at least 4 DIMMs to enable dual channel. If you are not running dual channel, you *will* see a sever hit to your RAC. This has been confirmed over on SETI.

However, once you have at least 4 DIMMs, you should also have 512mb per thread at a minimum. That will be enough for most projects. For some like Predictor (for now), you really need 1gb per thread.

These are minimums to prevent slowing down. As long as you have enough, adding more will not speed up anything.

---

Reno, NV
Team: SETI.USA

I'm running BOINC on a Mac Pro (4x2.6 Ghz, 1 GB RAM) and I'm thinking of adding another gig. What effect, if any, is this going to have on either RAC or system performance with BOINC running?

For Xeon systems (including Mac Pro), you need at least 4 DIMMs to enable dual channel. If you are not running dual channel, you *will* see a sever hit to your RAC. This has been confirmed over on SETI.

However, once you have at least 4 DIMMs, you should also have 512mb per thread at a minimum. That will be enough for most projects. For some like Predictor (for now), you really need 1gb per thread.

These are minimums to prevent slowing down. As long as you have enough, adding more will not speed up anything.

actually,the S5000 motherboards are "quad channels". If you put 2 modules only, you ll be dual channel (Same for MAC)

A XEON PC with 8 cores should at least run with 2Gigs, the performance increase to 4Gigs is neglisable, but make you "confortable"

If you run on MAC, offer yourself 4Gigs, and you ll stop seeing your HD flashing.


who?

More memory is always better. R@H uses about 100-120MB per thread!

---

What dows DIMM mean, exactly? Is that the memory card, or a GB of RAM?
What are channels? I'm using 4 processors. Are channels something different?
If threads use 150 MB each, shouldn't 1 GB be plenty?

My objective here is to optimize BOINC's performance and have enough memory left over to runn other programs and I suspect 1 GB isn't enough. There must be some benefit to loading up a computer with up to what, 16 GB of RAM? I just want to know if a $300 investment will make my computer run a little better and keep me and my wife happy with it.

---

Glans, BOINC has a few settings that are intended to give you some control over how much resource it consumes, and allow you to accomodate a number of individual situations. Could you let us know how your preferences are set? And how many hours a day someone is using the computer as compared to number of hours per day it is typically powered on and could run BOINC?

Here are some ideas:

Set the maximum number of CPUs for BOINC to 3, that way one is always available for a user.

Set BOINC to not run when the computer is in use, but also set to leave applications "in memory" so you preserve what you are working on. The memory referred to in that setting is VIRTUAL memory.

Set BOINC to limit it's memory use to a smaller fraction of memory then you presently allow.

You should be able to find a balance, with only a minor loss in your BOINC work production, which will relieve much of your usability issue, without requiring an upgrade at all.

---

Rosetta Moderator: Mod.Sense

Based on what you just said, I'm about to change my settings to save apps in memory but until then, here are my current settings and stats:
% of time BOINC client is running: 87%
% of time work is allowed: 84%
[/br]
Processor usage:
Do work while computer is in use: No
No restriction on time of day
Leave apps in memory: No
# of processors used: 4
Use at most: 100% od CPU time
[/br]
Disk and Memory usage
Use at most: 70 GB disk space
leave at least: 1 gb free disk space
use at most: 75% of page file
[/br]
Network usage:
connect to network: every 3 days
Maximum up/download rate: 5 KB/s

---

You skipped a few important settings:

Use at most xx% of memory when computer is in use
Use at most xx% of memory when computer is idle

These will help you control things so that it is quicker to start other applications. If you limit the amount of memory BOINC is allowed to use, you can force it to leave some for your other applications.

Leaving applications in memory will improve your efficiency, because every time BOINC gets started crunching, it takes a while (anywhere from 20min to a hour or more, depending on the WU) before it does enough work to reach a checkpoint. And with your setting NOT to do work while the computer is in use, if the user comes back before a checkpoint is reached, that work is lost when you do not leave the application in memory. It doesn't harm anything. But it doesn't speed your user experience any great deal either, so why not preserve the work?

---

Rosetta Moderator: Mod.Sense

[quote]You skipped a few important settings:

Use at most xx% of memory when computer is in use
Use at most xx% of memory when computer is idle

Since my last post I upgraded to 5.8.11. It looks like they are new to this version so I didn't have them before. Anyway, they are now set at 50% in use and 100% when idle.

So, if a thread uses about 150 MB, should I set it to use about 60% of my 1 GB of memory?

I'd rather not cut back to 3 processors yet. That would be a whole 25% reduction. Of course, it it means that the missus won't impose a 100% reduction I'll look into it, but I'll explore the other options first.

---

On a few slower/lower memory machines, users reported "sluggish" behaviour when using other programs. These settings were invented to provide those users with a way to limit the ram available to boinc projects, and not force them to stop contributing all together. I've got mine set to 100 each and have yet to see any sluggishness, but then I have the luxury of only using my fastest machine/s for everyday things and leave the rest to just do boinc.

You don't need to try and match useage to the settings, but can if you wan't. The higher the setting, the less frequently swap space will be utilized. Swap space if very slow compared to L1, L2 or memory access.

On a few slower/lower memory machines, users reported "sluggish" behaviour when using other programs. These settings were invented to provide those users with a way to limit the ram available to boinc projects, and not force them to stop contributing all together. I've got mine set to 100 each and have yet to see any sluggishness, but then I have the luxury of only using my fastest machine/s for everyday things and leave the rest to just do boinc.

You don't need to try and match useage to the settings, but can if you wan't. The higher the setting, the less frequently swap space will be utilized. Swap space if very slow compared to L1, L2 or memory access.

Also remeber Macs are very memory hungry. Most of my macs at work will idle with about 400 - 600 MB of ram used after a fresh reboot with nothing running. Try turning off unused widgets, and you need at least 512MB per core and a mac. I have 2GB in my core 2 duo IMac and with only boinc running I have about 800MB free on average. I have my boinc client set to the defaults and running always. I have had no issues with slow performance with Adobe CS apps or surfing. So with Macs the more memory the better.

---

Just in case you were wondering, DIMM means Dual In-line Memory Module and allows two sticks of RAM to run at twice their normal clock speed (i.e. 2x400MHz PC3200 RAM to run at 800MHz, so making it effectively PC6400 RAM) but only works on motherboards with this function. You can tell by opening up your computer and seeing if your RAM slots are alingned in sets of two and every pair is a different colour. The performance impact on a project like Rosetta with DIMM's is negligible and is more suited to reducing the bottleneck of data flowing between the memory and CPU in intensive apps like games and movie editing. Even a quad-core comp should be fine.

---

guys, this thread is really old! ;)

The performance impact on a project like Rosetta with DIMM's is negligible and is more suited to reducing the bottleneck of data flowing between the memory and CPU in intensive apps like games and movie editing. Even a quad-core comp should be fine.

Considering the impact of cache on Rosetta throughput, I'd expect that low memory latency and high throughput make a big difference here.

---

I believe DIMMs, which refers to a general construction of the RAM module, is being confused with DDR, a more specific type of RAM which has higher throughput but requires matched pairs of modules.

---

I believe DIMMs, which refers to a general construction of the RAM module, is being confused with DDR, a more specific type of RAM which has higher throughput but requires matched pairs of modules.

Actually, either of those may work better with,or even require, matched pairs of memory modules. I recall needing matched pairs as far back as the DIMM modules needed for Pentium-II "brick" CPUs.

It is all a function of the motherboard design, which in turn is a function of the particular chip set being used as the main control logic for the motherboard. Some chip sets only need one set of DIMM or DDR or whatever kind of memory, but those chip sets are frequently limited to just a 32 bit (or 36 bit with ECC/Parity) data path, although some other chip sets may allow for you to put in either a single memory module or some number of matched pairs. For a 64 bit data path, you need two 32 bit wide memory modules of some particular type or another. This led to the development of much larger memory modules that have a 64 bit data path (or 72 bits with ECC/Parity). And then we get to the Mac Pro, which the original poster has, and that motherboard is designed for a 128 bit (or 144 bit with ECC/Parity) data path, which is twice as wide again.

Now, for the original poster, who is running a Mac Pro with four cores, the recommended memory is

Each memory slot can hold DDR2 PC2-5300 with a maximum of 4096MB per slot. (Not to exceed manufacturer supported memory.)

Maximum Memory: 32768MB
USB Support: 2.x Compliant
Standard Memory: 1024MB removable
Slots: 8 (4 banks of 2)

And, Crucial recommends pairs of those units, which are:

Module Size: 2GB kit (1GBx2)
Package: 240-pin DIMM
Feature: DDR2 PC2-5300
Specs: DDR2 PC2-5300 • CL=5 • Fully Buffered • ECC • DDR2-667 • 1.8V • 128Meg x 72

So, you can see from the above that he needs 240-pin DIMM units, and they do need to be in pairs. Crucial does not offer a 1 GB upgrade (which is presumably a pair of 512 MB modules). What you may get where you live is another question entirely.

Finally, for whatever it is worth, Crucial claims that the Mac Pro does not support dual channel memory mode (which you are presumably calling quad channel mode).

== Bill