Basic mem/cache questions about sys design for a SMP folding rig

[Varnel]

According to the "Team 32's Starter's, Buying, Building, and Farming Thread" (http://www.ocforums.com/showthread.php?t=511295), more cache = better ppd.

I'm wondering just how much memory does the WinSMP client really need? Would 512m suffice for an XP system? Or is it worth the extra cash to go for 1g.

On the other side of the coin, could the impact of having less cache be reduced by using high-speed low-latency memory? Also, is it important to be running memory in dual channel mode, or is single channel fine?

Trying to weigh the options and get a clearer idea on a direction to choose.

Thanks

[pscout]

With the some of the smp wu's like 2610's in win and 2609 in linux, doubling the cache from 2-4 MB can improve perf ~ 40%.

512MB will do barely atm for some smp wu's in windows but ok for most. it is ok in linux since there is less os memory overhead. Mostly i run 1Gb dual channel but now have a few 2gb rigs. I would not be suprised with the new v6 client to start seeing wu's that will need over 512 tho.

I haven't tried any single channel setups so have no measurments, but others have been using single channel without much perf impact. Again it will also depend somewhat on the wu's.

Tight timings are always better but faster memory can do better than tight timings. No measurements here with win or linux smp wu's to guage the difference. I expect which is better may also depend on cpu arch and mobo chipset and the tradeoffs could be different across the cpu architectures .. pentium, c2d, amd.

I am sure ChasR will have some comments.

[dfonda]

Get the 1GB 512 is just not enough any more.

could the impact of having less cache be reduced by using high-speed low-latency memory?

No you need the Cache. Its more important then main memory above 1gb or speed of same.

There are some pretty low prices for 1gb kits get dual channel if you can swing it.

I have these 2gb $113 http://www.newegg.com/Product/Product.asp?Item=N82E16820231087

[NedClocker]

With the some of the smp wu's like 2610's in win and 2609 in linux, doubling the cache from 2-4 MB can improve perf ~ 40%.
Holy cow. Thank goodness I have 4 MB cache. I'd hate to see a 2609 run any slower. :D



512MB will do barely atm for some smp wu's in windows but ok for most. it is ok in linux since there is less os memory overhead. Mostly i run 1Gb dual channel but now have a few 2gb rigs. I would not be suprised with the new v6 client to start seeing wu's that will need over 512 tho.

I haven't tried any single channel setups so have no measurments, but others have been using single channel without much perf impact. Again it will also depend somewhat on the wu's.

Tight timings are always better but faster memory can do better than tight timings. No measurements here with win or linux smp wu's to guage the difference. I expect which is better may also depend on cpu arch and mobo chipset and the tradeoffs could be different across the cpu architectures .. pentium, c2d, amd.

I am sure ChasR will have some comments.
I believe my mobo is single channel. I run one stick of 1gig ram. I had 2 sticks but took one out and saw zero perf impact. I've posted some of my tpf before.

[davekusa]

Get 2 x 512 or 2 x 1gb. If you need to pull one stick your performance drop will be minimal.

L2 cache is king. Quad core or 6600,6700,6420,6320

[Shelnutt2]

tighter timmings on the memory all the way.

Before my water pump took out my main rig, I experimented and running 470 FSB with memory at 4-4-4-10-6-30 (at 1:1 ratio). I got TPF on a 2609 of 18:07

Then I ran 485 FSB with memory 5-5-5-12-6-30 (1:1) and I was getting TPF of 18:05.

It took 15 FSB to match tighter timmings.

[Hack30]

cpu
4 mb cache

mem
1 gig ram (6400 or better)
dual channel - slight boost:-/
tight mem timings


and a good o/cing mobo
don't forget a decent psu


btw we would all all like to know what you finally get and how your making out with it.;)

[Varnel]

btw we would all all like to know what you finally get and how your making out with it.;)

Of course I will. Isn't that half the fun of folding?

I was kinda looking at the E4400, and thinking I could possibly make up for it with fast/tight memory... Its why I asked. That's been ruled out. :)

It'll be a bit of time yet before I can afford to make the plunge to c2d.... Depending on the route I go (eg: Frys & el cheapo ECS to start or otherwise) that amount of time will vary. The P35 chipset looks very interesting, and as I have $0 invested in DDR2, it might be worth my time to wait for the DDR3 boards to hit. Even if I don't get a P35, it should help drive down the cost on some of the other more expensive boards out there like the P965/650i's.

One of the things I have decided that I will do this time around is watercooling. It's been a long time since I wc'd a system (last was a K6-2), and the products available for that have come a long way. (Need a working 775 first!)

It has also been decided that it will be at least an E6320/E6420/E6600/E6700 class, although I might pickup a cheap Cele D 347 to make sure the bugs are worked out on the wc setup before applying it to expensive hardware--espically if I have a cheapie ECS to put it on. (I should probably ask around here first, I'm sure someone has a now unused socket 775 single core sitting around that doesn't have a home anymore.)

Memory is still up in the air, the OCZ FlexXLC stuff looks interesting, however I don't think I'm going to want more then 1g. I'd like a pair (of whatever) but I'll see how things go. Of course if memory keeps getting cheaper, that'll make it easier to justify getting 2g.

The first thing will be a $40-70 PCI-E vid card. I can shove it in my opty 165 system for now and pull the aging GF3 out.

[ChasR]

There is no real reason to consider the E6600 and E6700. Almost any E6320 or E6420 will match or exceed the OC of the more expensive cpus. You also shouldn't consider the 2 MB cache models. If you're building a new rig, there really isn't much reason to buy an el cheapo motherboard and wind up maxed out @ 300 MHz FSB with these chips. THe ASUS P5B and Gigabyte DS3 are relatively inexpensive boards that will let you take FSB well over 400. My current favorite is the P5B/E6420/DDR2 800 combo. You'll get 3 GHz without really trying and can use the stock HSF in a cool room though I recommend a better HSF. I'm not convinced water is worth the trouble and it absolutely isn't worth it, if its expense causes you to skimp on the motherboard or drop down to a 2 MB cache cpu. I used 2 GB ADATA DDR2 800 running 1:1 at 4-4-4-12. Win SMP results from yesterdays build @ 3.0 Ghz, which was my friends target OC rather than the highest OC:

Project : 2651
Core : Gromacs SMP
Frames : 100
Credit : 1760

-- CC-HTPC --

Min. Time / Frame : 13mn 56s - 1818.95 ppd
Avg. Time / Frame : 13mn 56s - 1818.95 ppd

THis is using a Zalman CNPS9500, noted more for its quiet than its cooling, running @ 49 while folding.
Linux SMP production should be higher a good bit (150ppd/GHz) higher . If you can get up enough money, forget about water if it lets you afford a Q6600. The Q6600 will produce > 1000 ppd/GHz on all the Linux SMP WUs .

[Varnel]

There is no real reason to consider the E6600 and E6700. Almost any E6320 or E6420 will match or exceed the OC of the more expensive cpus.

I was leaning towards those, but that makes it certain.

You also shouldn't consider the 2 MB cache models.

The only reason I was even looking at the E4400 was the lower FSB/higher Multi. Its not even on the list anymore.

If you're building a new rig, there really isn't much reason to buy an el cheapo motherboard and wind up maxed out @ 300 MHz FSB with these chips.

With the occasional specials at Fry's the el cheapo motherboard + c2d ends up being about $1-2 above newegg's price for just the c2d. It's practicly free, and would give me a place to put the c2d after upgrading to a quad in the fall. If I wait for DDR3 I won't go this route. I don't have any DDR2 right now, and I won't buy it just for an ECS mobo.

THe ASUS P5B and Gigabyte DS3 are relatively inexpensive boards that will let you take FSB well over 400. My current favorite is the P5B/E6420/DDR2 800 combo. You'll get 3 GHz without really trying and can use the stock HSF in a cool room though I recommend a better HSF. I'm not convinced water is worth the trouble and it absolutely isn't worth it, if its expense causes you to skimp on the motherboard or drop down to a 2 MB cache cpu. I used 2 GB ADATA DDR2 800 running 1:1 at 4-4-4-12. Win SMP results from yesterdays build @ 3.0 Ghz, which was my friends target OC rather than the highest OC:

Project : 2651
Core : Gromacs SMP
Frames : 100
Credit : 1760

-- CC-HTPC --

Min. Time / Frame : 13mn 56s - 1818.95 ppd
Avg. Time / Frame : 13mn 56s - 1818.95 ppd

THis is using a Zalman CNPS9500, noted more for its quiet than its cooling, running @ 49 while folding.
Linux SMP production should be higher a good bit (150ppd/GHz) higher .

Yeah, the Asus P5B looks like a good buy (added to a short list). I'm still interested in how the P5K3 reviews later this month (and the $ tag when it hits the streets). I have my reasons for wanting water (noise etc), not to mention living in southern CA with the hot summer on the way. I will get a good aftermarket heatsink tho, perhaps another big beast with a 120mm fan. Backup is nice.

If you can get up enough money, forget about water if it lets you afford a Q6600. The Q6600 will produce > 1000 ppd/GHz on all the Linux SMP WUs .
In the fall... :)

[pscout]

Looks like some price cuts coming July 22 from intel --- q6600 @ $266

http://www.hkepc.com/bbs/itnews.php?tid=789466&starttime=0&endtime=0

In the meantime i am not holding my breath for ddr3 at any reasonable prices anytime soon.

AMD isn't expected to get on the ddr3 bandwagon till late 2008.

And needing new chipset/mobos for intels isn't going to create much of a market for volume very quickly.

6420 looks like a sweet spot for a decent oc'ing mobo atm... and it won't need as fast memory as a 6320. 6600's are getting cheaper and the price difference to the 6420 is dropping, so for a less oc'ble mobo and slower memory it could work out ok too.

[Varnel]

Its offical, I'll be going DDR2 with my upcoming c2d system. I just ordered 2x Mushkin 512m XP2-6400 rows (5-3-3-8 timings, prod # 991470S) from their bargain bin area for $26 ea + s&h & tax. Total price came to just under $60. If their website was correct, there are 4 left @ that price.

I'm leaning towards the P5B for the motherboard.

[davekusa]

look out. July 23nd I will cement my place in the top 20.

thanks for the info pscout

[drshivas]

I'm leaning towards the P5B for the motherboard.

P5B series rocks. I have the P5B-E, see rig in sig. I'd love to drop in an E6420 for the extra cache.