Does RAM affect CPU Time?

[sangyup81]

hello all!

My Phenom II X4 @ 3.946MHz with 8 GB of DDR3-1600 RAM in Windows 7 64-bit does correlizer work units in half the time of a Mac Mini 2010 with Core 2 Duo Penryn 2.4 GHz with 2 GB of DDR-1066 RAM in Windows XP 32-bit.

Does the CPU alone account for this difference? Will adding more RAM to the Mac Mini improve times?

Correlizer is that new project that I run on CPU time. Each core does one work unit.

I also compared times of work units that give the same # of credits and the twice as fast pattern appears to happen all the time

 

[sangyup81]

I do see in http://www.boinc-wiki.info/BOINC_FAQ:_Performance#How_can_I_make_BOINC_run_as_fast_as_possible.3F

"Increased RAM capacity. The more RAM in the computer the merrier BOINC will be."

But the question is, does it affect the CPU time where I get the 2x difference like that

 

[waffleironhead]

Just curious, what are your correlizer times?
My athlonx4 @ 2.6 does a wu in about 25 minutes.
4 gigs of ddr2-800 win7 64 bit

 

[Philippart]

hello all!

My Phenom II X4 @ 3.946MHz with 8 GB of DDR3-1600 RAM in Windows 7 64-bit does correlizer work units in half the time of a Mac Mini 2010 with Core 2 Duo Penryn 2.4 GHz with 2 GB of DDR-1066 RAM in Windows XP 32-bit.

Does the CPU alone account for this difference? Will adding more RAM to the Mac Mini improve times?

Correlizer is that new project that I run on CPU time. Each core does one work unit.

I also compared times of work units that give the same # of credits and the twice as fast pattern appears to happen all the time

maybe their windows app is more optimized than their mac app.

i would only add more ram if you see in the taskmanager that your ram is full and the pagefile is used all the time. to my knowledge ram should only have a really minor effect

 

[TakeNoPrisoners]

That AMD processor has twice the number of cores and is almost twice as fast. That would be why. RAM is also way slower but it is mainly the CPU.

 

[sangyup81]

Just curious, what are your correlizer times?
My athlonx4 @ 2.6 does a wu in about 25 minutes.
4 gigs of ddr2-800 win7 64 bit

These are just my best times:

Phenom II x4 3.946: 974.11s or 16:14.11
Mac Mini WinXP: 2058.75s or 34:18.75
Mac Mini OSX 10.6: 1593.00s or 26:33.00

It looks like my T8600 (2.4GHz) is only 1:33 behind your 2.6 when we're both running 64-bit OSes! (Snow leopard is 64 bit)

maybe their windows app is more optimized than their mac app.

i would only add more ram if you see in the taskmanager that your ram is full and the pagefile is used all the time. to my knowledge ram should only have a really minor effect

According to the results, the 64-bit Snow Leopard outdid the 32-bit Windows XP. Looks like XP 32-bit isn't something correlizer is very optimized for

That AMD processor has twice the number of cores and is almost twice as fast. That would be why. RAM is also way slower but it is mainly the CPU.

It won't be the cores because each core does one work until separately. When I eliminated the 32-bit vs. 64-bit OS difference, it's no longer a 2x difference. More like a 63.5% bonus for the Phenom II now to match the 64.44% clock speed difference! Of course there's also the difference in cache. The Phenom II has 512k L2 per core (2MB total) and 6MB L3 shared. The Penryn has 3MB L2 Cache shared (effectively 1.5 MB per core) and no L3

Makes me want to underclock my Phenom II to 2.4 GHz to see how it does =P

 

[sangyup81]

I just realized I gave Run times and not CPU times. Here are the CPU times:

Phenom II x4 3.946: 968.63s or 16:08:63
Mac Mini WinXP: 1966.69 or 32:46.69
Mac Mini OSX 10.6: 1592.00s or 26:32.00

 

[waffleironhead]

So this program definitely benefits from the 64 bit os. Good to know. I'm surprised the penryn is slower than my ax4 even with the speed deficit.

 

[sangyup81]

You know I always figured Athlon II was equal to the Core2Duos that did not have ridiculous amounts of L2 Cache. Phenom IIs are only supposed to be a little faster unless you're running a memory intensive process that benefits from the L3 cache. It seems that the L3 doesn't help me much

 

[wayliff]

You know I always figured Athlon II was equal to the Core2Duos that did not have ridiculous amounts of L2 Cache. Phenom IIs are only supposed to be a little faster unless you're running a memory intensive process that benefits from the L3 cache. It seems that the L3 doesn't help me much

I realize this is kind of an old post but found it while searching for "Cache".

So does Cache play any role in crunching at all? or does it vary per project?
I am considering upgrading my brisbane cpu to a phII quad...so just wondering.

 

[ZipSpeed]

I realize this is kind of an old post but found it while searching for "Cache".

So does Cache play any role in crunching at all? or does it vary per project?
I am considering upgrading my brisbane cpu to a phII quad...so just wondering.

Not sure if this helpful but with Correlizer, it takes 15:32 to complete a task on my X4 640 @ 3.3 GHz. With my X6 @ 3.5 GHz, it takes 14:53. Judging by those two numbers, looks like clock speed is more important than cache.

 

[sangyup81]

I realize this is kind of an old post but found it while searching for "Cache".

So does Cache play any role in crunching at all? or does it vary per project?
I am considering upgrading my brisbane cpu to a phII quad...so just wondering.

Perhaps if these WUs were bigger but since they aren't probably not. What will help are getting more cores and clockspeed on that upgrade you're thinking about =)

 

[wayliff]

Perhaps if these WUs were bigger but since they aren't probably not. What will help are getting more cores and clockspeed on that upgrade you're thinking about =)

I am going to try to hunt for a 95w Thuban...and that would be nice.
I don't know if I will have it ready for this Correlizer challenge...

That way I can replace my dual core with my current quad core and then add the Thuabn into the mix...then I'll sell the brisbane...if I can.

 

[Plimogz]

bumping this to broaden the topic with regards to RAM speed as well as capacity (which was, I believe the OP's main focus)

So, what about it, anyone know if there's gains to be obtained by upping memory speed/bandwidth?

***

Well, I went ahead and increased RAM speed on my Phenom II from 1333 to 1600 while keeping timings the same, and there's absolutely no improvement.

 

[sangyup81]

bumping this to broaden the topic with regards to RAM speed as well as capacity (which was, I believe the OP's main focus)

So, what about it, anyone know if there's gains to be obtained by upping memory speed/bandwidth?

***

Well, I went ahead and increased RAM speed on my Phenom II from 1333 to 1600 while keeping timings the same, and there's absolutely no improvement.

The Phenom II can't take advantage of 1600 when the CPU-NB is at 2000. This is why 1333 is the official speed of the Phenom II. When you up the CPU-NB to at least 2400, you start seeing results in benchmarks. Unfortunately, I haven't been able to check this out for BOINC tasks yet

 

[wayliff]

I am going to try to hunt for a 95w Thuban...and that would be nice.
I don't know if I will have it ready for this Correlizer challenge...

That way I can replace my dual core with my current quad core and then add the Thuabn into the mix...then I'll sell the brisbane...if I can.

Just about to pull the trigger on a 1045T Thuban. Found some at directron and superbiiz! I am having final debates with myself...I am pretty sure I won't be able to resist...he he.
AMD Phenom II X6 Six-Core Processor 1045T AM3

Edit: Trigger was pulled. Found a $10 off coupon for superbiiz so it was under $140 shipped.