i7 with 1333mhz ram does it work? Answer is here!

[OldCorpse]

A lot of issues here. Yes, it recognizes the 1333, but can it access it at full speed... that is a separate issue. Memory management may interfere... why Apple set it as 1066 for default, I have no idea... I hope it wasn't simply to cripple it so it won't bump against the MP too much

 

[i7QuadCoreMania]

A lot of issues here. Yes, it recognizes the 1333, but can it access it at full speed... that is a separate issue. Memory management may interfere... why Apple set it as 1066 for default, I have no idea... I hope it wasn't simply to cripple it so it won't bump against the MP too much

Mind telling us what Memory you are running? I was running the Hyper X 1600mhz CL7(so it says) XMP, but only stayed stable for me like 15mins then crashed and won't get past the Apple logo and spinning gear.

If it still doesn't work Monday with the 1333 CL7 non XMP I am gonna stick with the 1066 variety.

 

[i7QuadCoreMania]

Thanks to the individual who pm'ed me, I have updated the 64bit tests on stock 4gb 1066mhz. My 1333mhz is due today I should have some updates by this evening, abeit most of you will be sleeping, due to me being in Hawaii.

 

[DoFoT9]

so recapping. 1333MHz memory is a chance of working but 1600MHz is out of the question?

 

[zaphoyd]

I think CAS latency 9 stuff is out. Not sure if they make any 1600Mhz CAS 7 though.. This is not surprising because a coworker of mine had trouble with CAS 7 in a 2007 iMac that shipped with CAS 5 even though the memory speeds matched exactly.

 

[i7QuadCoreMania]

so recapping. 1333MHz memory is a chance of working but 1600MHz is out of the question?

1600mhz ram detects at 1333mhz which I believe is the max the i5/i7s will run.

1066 CL7 ram is stock specs, so 1333 ram probably also needs to be CL7, the 1600 CL7 kingston sells is actually programmed to CL9, and as someone mentioned the XMP might have something to do with the instability.

 

[DoFoT9]

1600mhz ram detects at 1333mhz which I believe is the max the i5/i7s will run.

yes thats correct the max specifies 1333MHz

1066 CL7 ram is stock specs, so 1333 ram probably also needs to be CL7, the 1600 CL7 kingston sells is actually programmed to CL9, and as someone mentioned the XMP might have something to do with the instability.

i have no idea what this CL7/CL9 stuff is lol but in short, some varient of 1333MHz should work?

 

[Stingray454]

i have no idea what this CL7/CL9 stuff is lol but in short, some varient of 1333MHz should work?

In theory, yes.. But we don't know for sure until someone puts them in and tries some benchmark, stresstests and similar. Waiting eagerly for someone to test this

 

[DoFoT9]

In theory, yes.. But we don't know for sure until someone puts them in and tries some benchmark, stresstests and similar. Waiting eagerly for someone to test this

the fact that the 1600MHz RAM is downclocked to 1333MHz and recognised is an indicator that it could possibly work - and that the CL7/CL9 RAM was the wrong variant of RAM. maybe? i dont know haha.

 

[macchiato2009]

i have ask the question several times to different apple resellers

the ram will be recognized at 1333 but will not run at this speed

they have probably locked something on the mobo

perhaps to make a gap with the future MP which will use ram at 1333

 

[itommyboy]

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??

Because they "step" us along to upgrades with the rest of the industry. After all they will need to "spec bump" the new iMacs that will come out in only a few months or so. Not to mention as always bigger better faster = more heat.

 

[Chunkers]

Not to mention as always bigger better faster = more heat.

Apple would have to factor appreciable variation in to their design because all memory sticks are not equal. Couple that with the fact that 1333MHz SO-DIMM sticks are designed to go in laptops and the iMacs will support 4GB sticks, and the chance of thermals or power consumption being an issue are very small.

 

[fruitpunch.ben]

i have ask the question several times to different apple resellers

the ram will be recognized at 1333 but will not run at this speed

they have probably locked something on the mobo

perhaps to make a gap with the future MP which will use ram at 1333

I think the 1333mHz stuff will run on the i5/i7s, but I'm not sure if the speed difference will be appreciable.
The other factor is whether the speed makes much difference on the benchmark apps. As we've seen even going from 4GB to 16GB of RAM makes little difference on Geekbench, etc. because the only time you're going to see a speed difference in that senario is when the machine is under heavy load and the benchmark apps are not designed to test that.

 

[DoFoT9]

I think the 1333mHz stuff will run on the i5/i7s, but I'm not sure if the speed difference will be appreciable.

The jump to 1333mhz in a macpro is somewhere around 2 - 5%. And that is with desktop ram and QPI that actually gives some good bandwidth options. Quite insignificant imo but I'm sure some people would benefit.

 

[i7QuadCoreMania]

The jump to 1333mhz in a macpro is somewhere around 2 - 5%. And that is with desktop ram and QPI that actually gives some good bandwidth options. Quite insignificant imo but I'm sure some people would benefit.

See my updated post and scores on the first page, I am back at 1333mhz and stable.

 

[bdeitemeyer]

Awesome, congrats.

 

[fruitpunch.ben]

See my updated post and scores on the first page, I am back at 1333mhz and stable.

what the real question is though, is the 100 point jump because you have gone from 4GB to 8GB or from 1066 to 1333mHz.
If its at all possible can you test with 4GB 1333mHz so we can confirm whether there is in fact a speed increase in the same amount of RAM but different speeds?

Thanks heaps if you can do this.

Ben

 

[OldCorpse]

See my updated post and scores on the first page, I am back at 1333mhz and stable.

Congrats. But I'll hold off on the champagne until you've been running with this for several days without problems... as we know, in the past, the issues didn't start popping up until later...

Here's to hoping for the best!

 

[jonwd7]

Congrats. But I'll hold off on the champagne until you've been running with this for several days without problems... as we know, in the past, the issues didn't start popping up until later...

Here's to hoping for the best!

This is first iMac with the memory controller integrated into the CPU. I foresee no issues myself (why I bought the same RAM as the OP almost two weeks ago), and I don't see how past issues have any relevance to the new iMacs, because of the integrated memory controller.

We know the CPUs that ship from Intel support 1333MHz by default, and since the EFI in the iMac has allowed 1333MHz RAM to run at its SPD-rated speeds and timings I don't see what else could possibly affect the stability of the RAM at this speed. AFAIK support for 1600MHz RAM by the CPU is not official and would rely on the motherboard enabling (or officially supporting/defaulting to) this speed so we can deduce that since the iMac did not support operation at 1600MHz (by defaulting to 1333MHz) that the instability he experienced then is probably due to the lack of 1600MHz support, and also that it was XMP-based RAM, which probably has a small list of motherboard vendors that officially support XMP.

Anyway, I can't wait to finally get my iMac, and when I do I will post my experience here with the 1333MHz RAM! I think I've had the RAM sitting all alone here for a week now... *sigh*

 

[OldCorpse]

This is first iMac with the memory controller integrated into the CPU. I foresee no issues myself (why I bought the same RAM as the OP almost two weeks ago)[...]

Regardless, there's something else I wonder. You said you bought the RAM already. We buy the RAM to make our iMacs more powerful. If you buy the 1333, that's presumably because you expect superior performance. But by the same token, if you buy it in 2GB sticks, you are limiting your options down the line... what if one day you wanna go 16GB? If you go ahead, you'll have to toss all the 2GB sticks and re-buy it all in 4GB chunks. Seems a waste to go to all this trouble with 1333 only to toss it...

 

[jonwd7]

...snip...

I know I'm never going to be upgrading to 16GB. By the time I'd want 16GB in a computer, I'd have a new computer.

I may one day add a slimline, slot-loading Blu-Ray drive (can be had for $150-$200), and an SSD, but those are worthwhile investments. Whereas moving from 8GB to 16GB would not.

Also, when 4x4GB sets may be cheap enough to purchase, you can think of it as what price it costs to double your RAM. Say the full 16GB may cost only $450 in a year, that's about twice what I paid to go from 4GB to 8GB. 8GB of the 1333MHz RAM was only $217.99. A small premium compared to the $200 upgrade cost for ONLY 4GB of RAM through Apple. (Plus, the Kingston HyperX 1333MHz was only $1 more than the Kingston 1066MHz RAM.) So speed notwithstanding I basically paid $217.99 for 4GB more RAM. However, when people talk about saving a buck to upgrade from 4GB > 8GB with 3rd party RAM, I chuckle because there is no way in telling if your mixed matched pairs are going to lead to any problems down the road, so if you're going to go from 4GB > 8GB you may as well go though Apple.

So, I'm only paying $18 more for 8GB of 1333MHz RAM as compared to 8GB of Apple's 1066MHz stock RAM. I think that's a fine deal.

Now take into account that with EITHER configuration (1066 vs 1333), you're going to have to scrap all your RAM to upgrade from 8GB to 16GB. So I'm not sure why you're using this fact against 1333MHz RAM only, when it applies to 1066MHz RAM as well. So I guess now I'm not sure what your point was?

Whatever it may have been, I'm very happy in paying an extra $18 for the higher speed RAM.

 

[i7QuadCoreMania]

I may one day add a slimline, slot-loading Blu-Ray drive (can be had for $150-$200), and an SSD
I paid to go from 4GB to 8GB. 8GB of the 1333MHz RAM was only $217.99. A small premium compared to the $200 upgrade cost for ONLY 4GB of RAM through Apple.

Those are the upgrades I'm looking at as well, I'd do them already but the Thermal sensor is holding me back. I am waiting for an official word from OWC if the come up with a better solution than shorting the wires to keep the temperature at low all the time.

I was running a WD 300gb Velociraptor in my last 24" iMac. I already have an Intel X25-M 80gb 2G in my Dell 10v Mod.

I ordered a bone stock i7, cause I knew the ram upgrades from 4 to 8 were cheaper than $200 apple charges, this is also why I went to 4 sticks of 2gb 1333mhz.

For what its worth, my i7 has been stable for the past few hours, which is farther than the last set of ram took me.

 

[OddHead]

So, news about stability?

Are the SODIMMs you bought Kingston ones? What model number?

 

[Rezox]

KHX1333C7 memory does not fit in the iMac. Did you take the heatsink off somehow?

 

[KopThat]

It's been a while since I have delved in to all this techie stuff, but
even though it is now reporting that all the RAM is 1333MHz ( even the standard 1066MHz ) with the Frontside Bus running at 1066MHz doesn't that limit how fast the memmory channels will be read ?

Is the System misreporting the speed of the RAM ?