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Cache memory bandwidth

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March 21, 2006 6:22:14 AM

I was running a memory test the other day, the one at the beginning of SUSE linux install, and it stated that the L1 Cache was - 16,476MBps, and L2 Cache was - 3,925MBps.

Is this normal? What Frequency do L1 and L2 cache run at?

Also it stated my DDR400 is only 1,602MBps, you and I both know it is supposed to be around 3200,MBps. Maybe the memory test has measured these speeds wrongly? Because I would have thought that all these speeds are suposed to be faster, especially the L2 Cache.

(AMD ATHLON 64 3200 VENICE, ASUS A8N-SLI DELUXE)

More about : cache memory bandwidth

March 21, 2006 5:47:31 PM

Quote:
I was running a memory test the other day, the one at the beginning of SUSE linux install, and it stated that the L1 Cache was - 16,476MBps, and L2 Cache was - 3,925MBps.

Is this normal? What Frequency do L1 and L2 cache run at?

Also it stated my DDR400 is only 1,602MBps, you and I both know it is supposed to be around 3200,MBps. Maybe the memory test has measured these speeds wrongly? Because I would have thought that all these speeds are suposed to be faster, especially the L2 Cache.

(AMD ATHLON 64 3200 VENICE, ASUS A8N-SLI DELUXE)


Due to cache misses and latencies, your L1 Cache and L2 Cache will be different by alot, and 16GB/s for L1 Cache is good for the 3200+, I believe my 3700+ gets about 18GB/s. Since you have socket 939, you should be getting at least 4.5GB/s, even with valueRAM. A friend of mine has Kingston Value RAM @ DDR400 and he gets 6GB/s on DFI Lanparty (not sure which one) so you're really off on your RAM speed unless you're running Single Channel.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
March 21, 2006 7:16:26 PM

Cheers for the reply. Yeah, you are right about the single channel, I'm getting another module to make it 1GB dual channel as soon as I possibly can. Nice one. Looks like i'll be off to buy some more RAM.
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a b à CPUs
March 21, 2006 8:05:51 PM

Quote:
I was running a memory test the other day, the one at the beginning of SUSE linux install, and it stated that the L1 Cache was - 16,476MBps, and L2 Cache was - 3,925MBps.

Is this normal? What Frequency do L1 and L2 cache run at?

Also it stated my DDR400 is only 1,602MBps, you and I both know it is supposed to be around 3200,MBps. Maybe the memory test has measured these speeds wrongly? Because I would have thought that all these speeds are suposed to be faster, especially the L2 Cache.

(AMD ATHLON 64 3200 VENICE, ASUS A8N-SLI DELUXE)


also depends on what apps you use to benchmark, like Memtest will post my P3's ram speed at like ~300mb/s where as sisoft sandra will post ~1000mb/s
March 21, 2006 9:35:39 PM

How come memory tests get results so far off sometimes? Do latencies really affect bandwidth that much?
I am using Corsair ValueSelect DDR400 (CAS2.5, Even though the CAS is pretty good I think the other timings aren't so good, but I'm new to latencies)
The way I was thinking was that DDR400 Single Channel- 3GBps approx
and Dual Channel 6GBps approx. Find it hard to believe that latencies could effect it that much.
March 21, 2006 11:02:38 PM

Hmmm... you should see a theoretical bandwidth of 3.2GB/s in single channel mode. It's strange that the benchmarking program reported 1.6GB/s (exactly half of what it's supposed to be).

Do you have any other memory benchmarking programs? I question the accuracy of the one you're using...

Also, are you 100% positive the RAM is running at the correct clock speed?
March 21, 2006 11:22:46 PM

Quote:
I am using Corsair ValueSelect DDR400 (CAS2.5, Even though the CAS is pretty good I think the other timings aren't so good, but I'm new to latencies)


I run 2 GB (4 x 512mb) of Corsair ValueSelect DDR400. Latencies are shown below from CPU-Z:


Not too bad for the price of the ram if you ask me.
March 22, 2006 2:11:51 PM

Yeah those latencies pretty much the same as what is says in my BIOS, and the clock is definitely at the right speed.
So yeah it must be a memtest problem
Cheers
a b à CPUs
March 22, 2006 6:33:19 PM

Quote:
Hmmm... you should see a theoretical bandwidth of 3.2GB/s in single channel mode. It's strange that the benchmarking program reported 1.6GB/s (exactly half of what it's supposed to be).

Do you have any other memory benchmarking programs? I question the accuracy of the one you're using...

Also, are you 100% positive the RAM is running at the correct clock speed?


My old celeron 2400 (northwood) with 512mb DDR266 dual channel ram hits 1.5gb/s max in sisoft sandra.

all depends on software used to benchmark.
March 22, 2006 6:48:20 PM

Yeah valueRAM (from almost anyone) is a good deal if you don't plan to overclock.
March 22, 2006 6:50:21 PM

Quote:
Yeah valueRAM (from almost anyone) is a good deal if you don't plan to overclock.


I have some value RAM of Kingston that gets higher efficiency than my PC4000 OCZ. 94% vs. 88%.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
March 22, 2006 6:56:33 PM

I would imagine the PC4000 stuff has higher latencies?
March 22, 2006 6:58:08 PM

Quote:
I would imagine the PC4000 stuff has higher latencies?


3-3-3-8 (Kingston) vs. 3-3-3-7 (OCZ), the PC4000 is @ 225MHz and the Kingston is @ 184MHz. Same thing with my PC3200 Crucial Ballistix, it got MAX 90% efficiency, but I have the ASUS A8N-SLI and the Kingston is in a DFI Lanparty, I blame the mobo.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
March 22, 2006 7:00:32 PM

I keep meaning to ask... what do video card do you use for your professional work? Quadro I'm guessing- but which one? SLI?
March 22, 2006 7:06:47 PM

Quote:
I keep meaning to ask... what do video card do you use for your professional work? Quadro I'm guessing- but which one? SLI?


I wish SLI, lol. The Engineering Lab has the FX5xx Series I believe(The crappy ones) but never cared to look for specifics. I only dropped by there a few times, my "professional" work involves MCSA, but I wouldn't call that "professional" o.O

PS: What kind of efficiency are you getting on your system for RAM? I would think 94% on that Value w/ DFI means ASUS = Sucks.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
March 22, 2006 7:44:09 PM

I use a QuadroFX 3000 in my office. It's starting to show its age with latest version of AutoCAD. My lappy has a QuadroFX Go 700- it's really only good for looking at small wireframe projects.

A QuadroFX 4500 in SLI would be sweeeeeeeeeeeet.

As for my RAM efficiency, I have no clue. I'm on secured computer which means I can't install programs or run very many. I don't even know what brand memory I have on this thing. LOL. It's got so damn many protections. If I open the case it gets reported to the security geeks.

Ironically it's a lenovo! hehehee...

-mpjesse
March 22, 2006 7:47:55 PM

Quote:
I use a QuadroFX 3000 in my office. It's starting to show its age with latest version of AutoCAD. My lappy has a QuadroFX Go 700- it's really only good for looking at small wireframe projects.

A QuadroFX 4500 in SLI would be sweeeeeeeeeeeet.

As for my RAM efficiency, I have no clue. I'm on secured computer which means I can't install programs or run very many. I don't even know what brand memory I have on this thing. LOL. It's got so damn many protections. If I open the case it gets reported to the security geeks.

Ironically it's a lenovo! hehehee...

-mpjesse


What about your home PC? I remember you talking about your new comp w/ the Opty 165.

Haha, security is fun. I remember setting up security on some computers that wouldn't let them shutdown, log into a website, or even open paint, haha. I love security ;D.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
March 22, 2006 7:54:06 PM

My home PC? I've run memory benches in the past, but I never kept a score. I think you might be confusing the Opty 165 statement w/ someone else. I've got a X2 4200+

I think I did contemplate getting a Opty 165 for OC'ing... but I never did get it.

Gimme a link to a benchmarking utility and i'll bench my memory when i get home. What u use? Sandra?
March 22, 2006 8:03:37 PM

Quote:
My home PC? I've run memory benches in the past, but I never kept a score. I think you might be confusing the Opty 165 statement w/ someone else. I've got a X2 4200+

I think I did contemplate getting a Opty 165 for OC'ing... but I never did get it.

Gimme a link to a benchmarking utility and i'll bench my memory when i get home. What u use? Sandra?


Ah, yes, the 4200+.

Here's a link: http://download.guru3d.com/sandra/

Yea, I use Sandra, it tells the Efficiency but it has a bug with it in 2T where it chops off over 1GB/s bandwidth on your score.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
March 22, 2006 8:47:46 PM

ewww... i'm running at 2T.
March 22, 2006 11:25:51 PM

Quote:
ewww... i'm running at 2T.


Real-world performance puts 2T @ less than 6% slower than 1T.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
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