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Old 2013-08-04, 15:05   #12
Jud McCranie
 
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On the third try I did get CPU-Z to install and not install anything I didn't want. The temp seems fine on the new i5 but it is a little hot on the old i7. I have cut both back to running three threads. On the i5, three gives better throughput than four. On the i7, the fourth one doesn't add much to the throughput, and it causes the fan to run faster because the CPU is hotter.

So what is the problem with the i5 - memory bottleneck or throttling back? The temp is not high on it. For a while it was running four exponents at 22ms per iteration. So the 3.0GHz i5 Ivy Bridge was matching the 3.4GHz i7 Sandy Bridge. Now it is quite a bit slower.
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Old 2013-08-04, 15:18   #13
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Quote:
Originally Posted by Jud McCranie View Post
On the third try I did get CPU-Z to install and not install anything I didn't want. The temp seems fine on the new i5 but it is a little hot on the old i7. I have cut both back to running three threads. On the i5, three gives better throughput than four. On the i7, the fourth one doesn't add much to the throughput, and it causes the fan to run faster because the CPU is hotter.

So what is the problem with the i5 - memory bottleneck or throttling back? The temp is not high on it. For a while it was running four exponents at 22ms per iteration. So the 3.0GHz i5 Ivy Bridge was matching the 3.4GHz i7 Sandy Bridge. Now it is quite a bit slower.
Just curious. Is the clock to spec in CPU-Z and is it detecting all your memory? "Memory" tab
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Old 2013-08-04, 15:37   #14
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Is the i5 system a single memory stick? It sounds like bad memory bottlenecking, but usually at those exponents there is no problem with 2 tests and little slowdown with 3. If you have just one stick of RAM, you only have half the bandwidth available on the board. If the board offers overclocking options, you could mess with speed changes to test if heat is the problem; I once undervolted a CPU at stock speed to cure a throttling problem.

ECM and P-1 take little memory bandwidth, and are likely to pay dividends for SOB. You can run these on the cores deemed unhelpful for Prime95.
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Last fiddled with by VBCurtis on 2013-08-04 at 15:39
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Old 2013-08-04, 16:06   #15
Jud McCranie
 
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CPU-Z does show the correct CPU speed and it detects the memory. (Speccy does too.)

About the memory, right now I have three sticks in the i5. I knew it was coming with 4GB and can be expanded to 16GB. (I know you get better performance with pairs of memory sticks.) When I ordered it, I didn't know if the 4GB would be on one stick or two (I assumed two). I ordered 8GB (two sticks) and had them ready to install when the i5 arrived. It came with one stick of 4GB. I added the two sticks, for a total of three sticks, 12GB. I ordered another 4GB stick which should arrive in a couple of days. That may have some effect.
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Old 2013-08-04, 17:33   #16
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Incidentally, slot #2 was the one that was vacant.

It came with a stick of 12800 CL=11. The two sticks I added were 10700 CL=9. The one I ordered is another 12800.

I was trying to rearrange them so the matching pair are in corresponding slots. The manual doesn't say and the only thing on the motherboard that I can determine is that the slots are black, blue, black, blue. I assumed that the ones with the same color are the matching ones, so I did some swapping. Now #1 and #3 are the 10700, #2 is the 1280, and #4 is vacant. But the iteration times went from 29 to 30ms.
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Old 2013-08-07, 01:03   #17
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Get rid of the third stick until the fourth one comes in. I don't know what 3 sticks will do but I can only imagine you're getting single-channel bandwidth. If this is in fact the case, then your bottlenecking issues will vanish.

Intel's processors can take some serious heat. Mine is currently running in a range that would almost immediately kill an AMD. To help with thermal issues, you may want to consider adding a fan or getting a better heatsink if you're using a stock heatsink. A coolermaster hyper 212 is your best bet if it can fit in your case.

On the other hand, it doesn't sound like a thermal issue at all. Try removing the single stick first. You're right about the colours. Also, from what I've seen, motherboard manufacturers typically have more confidence in the memory slots furthest away from the CPU. This is usually for overclocking purposes, but when you're not populating all four, you might as well use those.

If your RAM is good quality, particularly the 10700, you might be able to overclock it to the same settings as your 12800. RAM also has a frequency (think of ticks per second) and the timings (CL9 usually indicates something like 9-9-9-24) are the number of ticks the memory gets to do whichever stage of reading or writing memory it is at. So, CL11 gets eleven ticks during which to do the first step, whereas CL9 only gets nine. On the flip side, the CL11 is clocked higher so the overall latency might be about the same.

The reason I bring this up is your RAM may be able to handle the faster frequency if you loosen the timings. Looser timings are typically associated with snappier response and higher frequencies with better overall bandwidth, which is what you really need.
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Old 2013-08-07, 01:36   #18
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Quote:
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Intel's processors can take some serious heat. Mine is currently running in a range that would almost immediately kill an AMD.
What kind of heat are we talking about here?
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Old 2013-08-07, 01:40   #19
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Quote:
Originally Posted by TheMawn View Post
Get rid of the third stick until the fourth one comes in. ...

Intel's processors can take some serious heat. ...

On the other hand, it doesn't sound like a thermal issue at all.
The new stick is due to arrive tomorrow, so I'm not going to bother to take the third one out. However, I was getting 22ms with three sticks the first day, now it is 29-30.

I don't think heat is an issue. Right now I have it on its side, and the air intake vents are on the top. Yesterday I inadvertently put a phone book on top of it - blocking the air vents. The fan sped up and got loud. Until then the fan had been very quiet. I realized what I had done and took the phone book off. Within probably a minute the fan was somewhat quieter and within a few minutes it was back to very quiet.

Last fiddled with by Jud McCranie on 2013-08-07 at 02:07 Reason: add something
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Old 2013-08-07, 02:11   #20
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Actually I was getting 22ms on four workers on the i5 at first - matching my i7. Then it went to 40. I cut it back to three workers to get 29-30. I assume the iteration times it gives are accurate.
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Old 2013-08-07, 05:07   #21
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Hmm well if it's arriving soon then yeah don't bother.

Heat: AMD's latest get pretty prissy around 60C. My Ivy Bridge is running in the mid 70's. Throttling happens at 105C. Which is good because Ivy Bridge runs 10C-15C hotter than it needs to.
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Old 2013-08-07, 07:55   #22
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My Sandy Bridge i7 is running about 73C running three workers. With four workers it was about 78C. With four workers, the fan was on a higher speed. At 73 the fan doesn't run nearly as loudly, but louder than the IB i5.
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