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i7QuadCoreMania

macrumors 6502
Original poster
Nov 10, 2009
282
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so I went on a limb, ordered 2 pairs of 2gb (8gb) Hyper X DDR3 1600mhz CL7 from newegg.

here is my stock configuration:

Screenshot2009-11-18at64702PM.png


Screenshot2009-11-18at64738PM.png


after the install:
Screenshot2009-11-18at103559PM.png


Screenshot2009-11-18at102734PM.png


So this answers the burning question, I am running 1600mhz ram but the system only clocks it at 1333 so the fastest you can run is 1333 and the system recognizes it without any other mods or hacks.;)

Love my i7:D
 
Can you do some benchmarks with 4GB 1067Mhz vs. 4GB 1333Mhz RAM installed.
 
would love to see some benchmarks with the different types of memory in... question is why didn't apple put 1333 in the i7 machines??
 
Have you tried mixing 1066 and 1333 modules?

I bought 2x2 1333 modules and i'm not sure if it will work...
 
Wow, nice bravery to be the guinea pig...congrats. Makes me wish I would have waited for something like this, now I'm "stuck" with 8GB of the Apple RAM on my i7. lol
 
So I just bought a crucial 4gb DDR3 sodimm kit for my iMac for about 50 bucks during a sale. Its 1066. I think the Apple stock ram is also 1066. If I want to take advantage of 1333 speed, I would need to upgrade all 4 sodimms to 1333 correct?
 
Geekbench benchmarks please!!

Run 64-bit version (if available) both with 1066 and 1333, that would be awesome to see.. Can't wait :)
 
Geekbench benchmarks please!!

Run 64-bit version (if available) both with 1066 and 1333, that would be awesome to see.. Can't wait :)

Be sure to run Geekbench two or three times. When I used faster memory in a Mac Pro, the memory test was faster on the first run but slowed down to "normal" speeds in second and third run. It appears that the faster memory is throttled down.

Also, if you use DigiLoyd Tools memory test, you can stress all available memory. Geekbench's memory tests only use a small portion of memory.
 
I look forward to some benchmarks are well, hopefully we will get something by the weekend to look at. Imho, unless the numbers blow me off my seat, I really think spending ~$85 for 4gb more of 1066 for a total of 8gb is the best bet for now. When the price of the 4x4gb drops, then it might be the right time to try out the 1333 ram. Not sure it makes sense to buy 2x4gb 1333 (cost) or 4x2gb 1333 (would have to throw out when getting 16gb in future) right now. Might as well use the 2x2gb that come stock and add another 2x2gb.
 
There was a screenshot from someone else on another topic, showing his geekbench result with 16 gigs of 1333mhz ram. The 64 bit result was only 9670 or something-- only a 3% increase over stock figures.

But I do agree geekbench isn't the best bet to test ram capacity to its fullest potential.
 
There was a screenshot from someone else on another topic, showing his geekbench result with 16 gigs of 1333mhz ram. The 64 bit result was only 9670 or something-- only a 3% increase over stock figures.

But I do agree geekbench isn't the best bet to test ram capacity to its fullest potential.


I had some stability problems last night after I posted and ran some tests. It seems the ram I installed is RATED 1600mhz CL7 Intel XMP, but the onboard SPDs are programmed for CL9:mad:

I did manage to get a 32bit test out. Score was 8390 (If I recall correctly) I looked at a test from another i7 with 4gbs of ram was somewhere 8350, so there is "a bit" of a performance boost but I can't say 100% till I get the stability problems sorted. (I dont have a registered ver of Geekbench to run the 64bit tests, the OS wont make use of the extra ram on 32bit tests)

I re-ordered another set, these are rated for 1333mhz CL7, but they wont be here till Monday, so for now I am going to re-install the stockers and wait till my new order arrives from newegg.:(
 
I did manage to get a 32bit test out. Score was 8390 (If I recall correctly) I looked at a test from another i7 with 4gbs of ram was somewhere 8350, so there is "a bit"

Is 40 points really a performance boost? I mean 40 points is 40 points, but is that within the standard margin of error? Did you repeat the tests several times and average?
 
Is 40 points really a performance boost? I mean 40 points is 40 points, but is that within the standard margin of error? Did you repeat the tests several times and average?

Which is why I said "a Bit" you'll have to wait till monday, Im going back to the stockers till the 1333mhz CL7 (SPD programmed) chips arrive, Gives me plenty of time to bench the stockers at 4gb before the new chips arrive, my bigger worry was the system would only detect the ram at 1066mhz.;)
 
I had some stability problems last night after I posted and ran some tests. It seems the ram I installed is RATED 1600mhz CL7 Intel XMP, but the onboard SPDs are programmed for CL9:mad:

I did manage to get a 32bit test out. Score was 8390 (If I recall correctly) I looked at a test from another i7 with 4gbs of ram was somewhere 8350, so there is "a bit" of a performance boost but I can't say 100% till I get the stability problems sorted. (I dont have a registered ver of Geekbench to run the 64bit tests, the OS wont make use of the extra ram on 32bit tests)

I re-ordered another set, these are rated for 1333mhz CL7, but they wont be here till Monday, so for now I am going to re-install the stockers and wait till my new order arrives from newegg.:(

Do you know if Apple's factory RAM is CL7, CL9 or other? Thanks :)
 
Do you know if Apple's factory RAM is CL7, CL9 or other? Thanks :)

The 1066 Ram is CL7, the stock Samsung chips I pulled from it were CL7, makes me suspect the programmed CL9 1600mhz chips (it says tested down to CL7 on Kingston's website:mad:) are the cause for the instability.

My new chips that are due monday (latest Tuesday) are programmed to CL7 and 1333mhz.
 
I'm fairly certain the reason for instability was simply that it had XMP. Who knows what the XMP profiles do internally and if Apple's EFI would support something like that.

The Intel page for it suggests a lot of changes:
Multiple SPD profiles
Enables preset or user-defined memory profiles that can be selected depending on usage model. For example, an aggressive low-latency profile could be used during intense gaming while the default memory setting can be used for everyday home computing, such as home office or web browsing.
Memory vendor specific SPD fields
Enables Memory Module suppliers to program their own capabilities and provide unique value to end users.
Easy overclocking (novice)
Enables end users to easily overclock their platforms by selecting the appropriate profile, instead of adjusting individual parameters in BIOS. Reselecting the default profile resets the platform to default setting.
Advanced overclocking (intermediate/expert users)
Expert users can manually change specific SPD parameters in the BIOS and save the profiles (platform/BIOS specific).
Fail-safe default boot
"First boot" with default JEDEC setting on a platform that supports DDR3 standard JEDEC specification (your standard DDR3 memory frequencies), ensuring base functionality. Then user can enter BIOS and manually change settings or use the Windows*-based Intel® Extreme Tuning Utility.
Any one of which could probably be making the iMac croak. I myself ordered 8GB of KHX1333C7 (same as your new order) last weekend, after ordering the iMac itself.

I'll be looking into your thread to see how the new RAM goes!
 
I'm fairly certain the reason for instability was simply that it had XMP. Who knows what the XMP profiles do internally and if Apple's EFI would support something like that.

The Intel page for it suggests a lot of changes: Any one of which could probably be making the iMac croak. I myself ordered 8GB of KHX1333C7 (same as your new order) last weekend, after ordering the iMac itself.

I'll be looking into your thread to see how the new RAM goes!

We shall know Monday, it shipped today.

I am back to stock and have run a few geekbench 32bit tests (Someone with a registered version who would like me to run 64bit tests pm me:D)
32bit Tests
Ran these tests 5x
Overall Memory
8152 3812
8210 3817
8149 3835
8289 3829
8404 3820
Averages
8241 3823 (rounding off the next integer)

64bit Tests
Overall Memory
8943 4622
8886 4582
8840 4599
8723 4555
8967 4632
Averages
8872 4598

Gonna try test again when I am back on 1333mhz 8gb CL7 ram monday, stay tuned.:D


*****EDIT*****
I am happy to report my second attempt at 1333mhz is working!!! I am back on 8gb of 1333mhz as of 1 hour ago and running completely stable at the moment tried a reboot and came up as normal!

32bit tests
Overall Memory
8353 4007
8382 4015
8314 4081
8357 4057
8276 4013
Averages
8336 4035

64bit Tests
Overall Memory
9070 4840
9154 4887
9014 4892
9033 4779
8943 4810
Averages
9043 4842

So, going from 4gb 1066mhz to 8gb 1333mhz, there seems to be a bump of 100 points in 32bit and almost 200 points in 64bit.

If there are other tests you peeps want me to run I'd be happy to oblige. (Keep in mind I wont swap back to 4gb 1066 if I am completely stable for the next few days that is :p)
 
I bet you get an even higher increase than that if you just simply downscale your monitor's resolution.
 
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