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New iMac, Upgraded Ram, But Ram Running @ 1333mhz

D

digitalfailure

macrumors regular
Sep 24, 2012
166
1
No worries :)

On the face of this thread I think I might buy another 16gb kit to ensure all my ram is the same speed.

Great 500px too Richard :)
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
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indy911 said:
CL11 RAM is not inferior, it just runs at a slower timing.
Click to expand...
The rest of your post was spot on, but I am confused why you said this.


If something can only run at a slower timing, which was found by testing, it must therefore be inferior, unless our definitions of inferior are different. Your statement is suggesting that the GPU in a 670 is not inferior to the GPU in the 680, it's just capable of "slower timing".

1600 MHz CL 9 is more expensive than 1600 MHz CL10 RAM, which is more expensive than 1600 MHz CL11 RAM. So how is it CL 11 is not judged inferior and then put into the budget memory? It's like saying that a BMW 320 is not inferior to the BMW M3. It's just slower. :D I guess it depends on what you think inferior means in the context.

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burninggarlic said:
This smbios was what I meant.
Click to expand...

Sorry, I have never seen that and was only aware of a Windows version. I do not know what it does and how it works in OS X. :)

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Richard Peters said:
Sorry yes, I didn't make myself clear there. I've got 32gb ram sitting here that's CL11, so I was wondering if I should swap that for something that's CL10. Going off on a slight tangent from the original thread topic, apologies :)
Click to expand...

It should work perfectly fine, since you are not mixing. So the best advice is to try it and see if the iMac is happy with it. If it's not, then return it.
 
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sjz88

macrumors member
Nov 30, 2012
70
0
Hum I really don't know what to do with my 16GB Crucial RAM.
Maybe put in ONLY the 16 GB from Crucial. Or ONLY the 8 GB from Apple?
How much of a different does CL 9 really make compared to CL 11? Will I even notice?
So what will be the fastest and best option in your opinion?
1.) 8 GB Apple RAM
2.) 16 GB Crucial RAM
3.) 8 GB + 16 GB = 24 GB combined Apple and Crucial

?
Thanks in advance!
 
A

Arman

macrumors regular
Aug 27, 2008
204
1
SoCal
Well I'm on the fence on what to do with my pair of Corsair CL10 sticks. I guess I'll wait and see what happens when I pop them in. Seeing as the price of the CL9 ram is almost double, I would say the best route is just to double up and go 32gb
 
I

indy911

macrumors newbie
May 8, 2012
11
0
theSeb said:
The rest of your post was spot on, but I am confused why you said this.


If something can only run at a slower timing, which was found by testing, it must therefore be inferior, unless our definitions of inferior are different. Your statement is suggesting that the GPU in a 670 is not inferior to the GPU in the 680, it's just capable of "slower timing".
Click to expand...

Your definition of inferior seems to be solely based on the CAS latency of a memory module. I think it is a little more subtle than that. Let's leave it at that.
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
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Arman said:
Can anyone actually confirm the Apple memory is CL9 and not CL11.
Click to expand...

You are right. Apple's RAM actually could be CL11, which would also explain what the OP is seeing. The tear downs so far by iFixit have been lacking in this type of information.
 
B

bflowers

macrumors 6502a
Jul 19, 2006
636
136
WilliamG said:
Good to know it's just the mixing of brands causing the issue. Shame that happens, though. And it seems the stock RAM really does come in slots 1 and 3. Also good to know!

And yes, I am everywhere, bahaha!
Click to expand...

Well, at least I was half right. Apple rep must not have known specifics, and just agreed with me. Apple did fill in the slots that are paired, just seems odd that they don't address them them differently, but that my be a physical issue with routing the leads on the board. Wonder if this has always been the case, as I've had a couple of desktops over the years with 4 slots... Although I think they always came full, and I always replaced them all.

Ah well, the advice to fill in the empty slots still applies. Thanks everyone for their contributions.
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
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indy911 said:
Your definition of inferior seems to be solely based on the CAS latency of a memory module. I think it is a little more subtle than that. Let's leave it at that.
Click to expand...

If a memory module needs to have a CAS latency of 11 to run at 1600 MHz, then it is inferior to a memory module that can run at 1600 MHz at CL of 9. Would you disagree with this statement?

There are of course other things that come into the equation, such as RCD, tRP, tRAS, tRC and CR. But when a memory has a low CL, it's normal for it to have better figures for all those as well.

Memory generally comes in 9-9-9 or 10-10-10. I have never seen some magical memory that has a high CL and then the other figures are amazingly fast. That would not make any sense whatsoever.

All of Kingston's Value RAM running at 1600 MHz is CL 11 (DDR3-1600 timing of 11-11-11 at
1.5V)

All of Kingston's HyperX Blu (entry-level high performance) RAM running at 1600 MHz is CL10 or CL9

As you go up the range, it's pretty easy to spot the pattern.

Without boring people here that had the fortune of not studying this at University, it is a safe guideline that when comparing memory running at the same MHz, the one with the higher CL is slower and inferior.

For those that are really bored, or interested, they can always calculate the calculable latency, bit time and cycle time and compare.
 
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A

Arman

macrumors regular
Aug 27, 2008
204
1
SoCal
Checked ifixit website. 21.5 ram is CL11. Assuming for now same us true for 27. Those with Crucial ram upgrade should be good to go.

http://www.ifixit.com/Teardown/iMac+Intel+21.5-Inch+EMC+2544+Teardown/11936/3
 

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sjz88

macrumors member
Nov 30, 2012
70
0
Arman said:
Checked ifixit website. 21.5 ram is CL11. Assuming for now same us true for 27. Those with Crucial ram upgrade should be good to go.

http://www.ifixit.com/Teardown/iMac+Intel+21.5-Inch+EMC+2544+Teardown/11936/3
Click to expand...

Good news thanks for sharing! So hopefully my 16GB Crucial RAM will run with 1600Mhz and the 8GB Apple RAM too. How can I see at what frequency the RAM is running? Is there a free application?
The money Apple wants for it's RAM is all the crazier if you consider it is CL11....
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
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Arman said:
Checked ifixit website. 21.5 ram is CL11. Assuming for now same us true for 27. Those with Crucial ram upgrade should be good to go.

http://www.ifixit.com/Teardown/iMac+Intel+21.5-Inch+EMC+2544+Teardown/11936/3
Click to expand...

Ahh, very good find. It looks as though it wasn't the iFixit tear down that was the problem. It was my speed reading and inability to click on all of the thumb nails.

It's probably safe to assume that the 27" also has CL11. I have to say that it does not surprise me that Apple would cheap out here, but it really makes the mind boggle when one considers the price of the memory upgrades.

Yes, those who have purchased Crucial's CL 11 kit are good to go and *should* be able to mix with Apple's RAM, but I still would not recommend it. Those that have purchased CL10 or CL9 kits will see their memory speed lowered.

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sjz88 said:
Good news thanks for sharing! So hopefully my 16GB Crucial RAM will run with 1600Mhz and the 8GB Apple RAM too. How can I see at what frequency the RAM is running? Is there a free application?
The money Apple wants for it's RAM is all the crazier if you consider it is CL11....
Click to expand...

Click on the Apple menu in the top left corner. Then click on "About My Mac". The information is there.
 
A

Arman

macrumors regular
Aug 27, 2008
204
1
SoCal
Jazwire said:
Just got my new 2012 iMac set up, I ordered it with 16 gb (2x8) , and then purchased a Corsair Vengeance Kit from Amazon (the one several people have linked in here) it is 1600mhz ram I'm looking right at the box as I type.

The model number of the ram confirms it is 1600mhz, CMSX16GX3M2A1600C10

But when I go to "About this Mac" it does show correctly 32GB, but it's running at 1333mhz not 1600mhz.

And if I go to Hardware/Memory it shows all 4 sticks running at 1333mhz.


Any ideas???
Click to expand...

Jazwire, can u pull the stock ram on your iMac and confirm the Model number/Cas Latency? A pic would be even better.
 
burninggarlic

burninggarlic

macrumors member
Nov 30, 2012
82
0
so now we have reached the conclusion?
just need to make sure the ram we need is 204 pin 1600MHz CL11 DDR3
right?
 
brock2621

brock2621

macrumors 65816
Jun 8, 2007
1,015
539
Kentucky
Um, So I just ordered 32gbs of ram for my 27" from OWC
(http://eshop.macsales.com/item/Other%20World%20Computing/1600DDR3S32S/).

How am I looking in context of all this?
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
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burninggarlic said:
so now we have reached the conclusion?
just need to make sure the ram we need is 204 pin 1600MHz CL11 DDR3
right?
Click to expand...

No. You only need that RAM if you're planning to add it to the stock RAM. And even then mixing different brands is not a good idea. Buy the RAM that you can afford that meets these specifications:

PC3-12800
(1600) DDR3
204-pin
SO-DIMM

It's best to buy the same sticks from the same manufacturer. 1600 MHz CL9 RAM will be faster than 1600 MHz CL10 RAM which will be faster than 1600 MHz CL11 RAM.

The really interesting question is how will the motherboard handle 1866 MHz CL10 RAM.

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brock2621 said:
Um, So I just ordered 32gbs of ram for my 27" from OWC
(http://eshop.macsales.com/item/Other World Computing/1600DDR3S32S/).

How am I looking in context of all this?
Click to expand...

You're looking fine, but you could have bought faster RAM. Real world difference? Not something that you would really notice.
 
burninggarlic

burninggarlic

macrumors member
Nov 30, 2012
82
0
theSeb said:
No. You only need that RAM if you're planning to add it to the stock RAM. And even then mixing different brands is not a good idea. Buy the RAM that you can afford that meets these specifications:

PC3-12800
(1600) DDR3
204-pin
SO-DIMM

It's best to buy the same sticks from the same manufacturer. 1600 MHz CL9 RAM will be faster than 1600 MHz CL10 RAM which will be faster than 1600 MHz CL11 RAM.

The really interesting question is how will the motherboard handle 1866 MHz CL10 RAM.

----------



You're looking fine, but you could have bought faster RAM. Real world difference? Not something that you would really notice.
Click to expand...

You are probably right.

I was trying to make this thread clear. The reason of 1600MHz just running with 1333MHz is because he bought CL10 ram and add it to the stock ram, which is CL11.

There are certainly more better and expensive options. But computer is not the only gear we are paying for (at least not me). I totally understand "buy the most expensive one you can afford". The strongest controversy for myself is, that I cannot afford all the most expensive ones, I have to make a choice. Ram is not the highest priority.:eek:
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
7,466
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burninggarlic said:
The reason of 1600MHz just running with 1333MHz is because he bought CL10 ram and add it to the stock ram, which is CL11.
Click to expand...
Correct.

There are certainly more better and expensive options. But computer is not the only gear we are paying for (at least not me). I totally understand "buy the most expensive one you can afford". The strongest controversy for myself is, that I cannot afford all the most expensive ones, I have to make a choice. Ram is not the highest priority.:eek:
Click to expand...
There will always be someone stronger, richer and have better toys than you so trying to chase the fastest is pointless.

But when it comes to RAM and the difference in price between CL11 and CL9 is normally the equivalent of a pair of cinema tickets and a pint of beer, then I don't think that argument applies. Unless you get by on pocket money.
 
burninggarlic

burninggarlic

macrumors member
Nov 30, 2012
82
0
theSeb said:
Correct.


There will always be someone stronger, richer and have better toys than you so trying to chase the fastest is pointless.

But when it comes to RAM and the difference in price between CL11 and CL9 is normally the equivalent of a pair of cinema tickets and a pint of beer, then I don't think that argument applies. Unless you get by on pocket money.
Click to expand...

I found the price of cl9 ram for mac 2012, which is more than $200/pair (2x8gb). So if I am going for 32 gb, it will cost over $500. Just for ram? No thanks. I can buy some filters from Lee or Tiffen with this money. The ram will just follow me max 5 years. The extra filters can follow me forever.

I am not arguing. I just hope you can get my point. I do not against yours. Because people do have different needs. ;)
 
theSeb

theSeb

macrumors 604
Aug 10, 2010
7,466
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burninggarlic said:
I found the price of cl9 ram for mac 2012, which is more than $200/pair (2x8gb). So if I am going for 32 gb, it will cost over $500. Just for ram? No thanks. I can buy some filters from Lee or Tiffen with this money. The ram will just follow me max 5 years. The extra filters can follow me forever.

I am not arguing. I just hope you can get my point. I do not against yours. Because people do have different needs. ;)
Click to expand...

Where are you looking and where do you live mate? Here is Kingston for $135 / 16 GBs

http://www.amazon.com/1600MHz-PC3-12800-Notebook-KHX16S9P1K2-16/dp/B008H7IGGI

Edit: Ok, so maybe it's a couple of pints of beer difference. :)
 
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