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Old 2014-10-03, 21:40   #34
petrw1
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Quote:
Originally Posted by Mark Rose View Post
Actually, there's a very simple way to tell: open the case and count the memory sticks. If you only one stick it's single channel. If there are two sticks immediately beside each other (no empty slots), it's dual channel.
I do know it only has 4G of RAM.

It would not surprise me a lot if there was only one 4G stick.
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Old 2014-10-03, 21:53   #35
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Quote:
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I do know it only has 4G of RAM.

It would not surprise me a lot if there was only one 4G stick.
That does seem low for a new machine.
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Old 2014-10-03, 21:58   #36
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Quote:
Originally Posted by Mark Rose View Post
That does seem low for a new machine.
IIRC, that is what the non-profit I work for is getting for the new Dell compact i5 desktops they've been ordering. A single DIMM would not surprise me, as 2 GB sticks are likely less cost effective than one 4 GB.
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Old 2014-10-03, 22:58   #37
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So if I were to assume it has one 4G stick it will almost certainly be memory bound....and not be able to perform anywhere near its potential.

Should I:
- only run 2 workers; one on 1 of the first 4 logical cores and 1 on the second set?
- run 2 workers but let them each have 4 logical cores?
- run 4 workers and let them fight it out knowing they will be slow but still produce more overall thru-put than 2 workers?
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Old 2014-10-04, 00:42   #38
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Quote:
Originally Posted by petrw1 View Post
So if I were to assume it has one 4G stick it will almost certainly be memory bound....and not be able to perform anywhere near its potential.

Should I:
- only run 2 workers; one on 1 of the first 4 logical cores and 1 on the second set?
- run 2 workers but let them each have 4 logical cores?
- run 4 workers and let them fight it out knowing they will be slow but still produce more overall thru-put than 2 workers?
I have two 2400 MHz dual-channel memory.. still bottlenecked.
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Old 2014-10-04, 01:56   #39
Prime95
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Quote:
Originally Posted by petrw1 View Post
So if I were to assume it has one 4G stick it will almost certainly be memory bound....and not be able to perform anywhere near its potential.

Should I:
- only run 2 workers; one on 1 of the first 4 logical cores and 1 on the second set?
- run 2 workers but let them each have 4 logical cores?
- run 4 workers and let them fight it out knowing they will be slow but still produce more overall thru-put than 2 workers?
Since we haven't ruled out thermal throttling, fewer workers is probably best. And since you probably have half the memory bandwidth of most Haswells, you are unlikely to see much gain from more than two workers. Thus, I'd run two workers and letting the OS figure out which logical CPUs to use may be best.

Sad.
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Old 2014-10-04, 03:31   #40
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Quote:
Originally Posted by petrw1 View Post
In fact in general I cannot even install extra software; at least nothing that requires any kind of Admin authority... i.e. nothing like CoreTemp or CPU-Z.
CPU-Z has non-install version. Just download and run. However, while running, it may ask for admin clearance. Can you try it out?
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Old 2014-10-04, 16:38   #41
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Can you open the PC case and clean up the dust of the cooler?
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Old 2014-10-04, 21:31   #42
petrw1
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Quote:
Originally Posted by pinhodecarlos View Post
Can you open the PC case and clean up the dust of the cooler?
PC is only a couple months old.
No need to dust yet unless ... wink wink ... good opportunity to inspect what is there.
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Old 2014-10-06, 22:20   #43
petrw1
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Default Well with 4 workers doing LL .... IT REALLY SUCKS

Per iteration time almost exactly DOUBLED from when 2 workers were doing LL and 2 were doing TF.

I'm going to see what happens when I stop workers #1 and #3.
Will #2 and #4 drop by half again ... or even more....

I'm am going to guess about the same and in the end I will be running TF on 2 workers and LL on the other 2.

Tune in tomorrow: Same Bat Time Same Bat Channel
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Old 2014-10-07, 02:35   #44
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If all 4 doing TF is slower per worker than 2 doing TF, you have a heat problem- probably a misaligned heatsink, maybe a non-functioning CPU fan. Testing all TF removes the memory bottleneck, I believe.

Two LLs could saturate single-stick memory throughput, but I would think TF's lighter memory use would allow LL to much-less-than-double when you add two TFs to 2 LLs; so I think you have a serious heat problem, rather than just a memory bottleneck.
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