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DDR3 RAM in NEW Macbooks, Macbook Pros

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lwongveros

macrumors newbie
Original poster
Jun 15, 2007
26
1
Hi everyone, I did a quick search on the forums and haven't seen anything regarding a doubt that I have....

We all know that the new Nvidia chipset being used in the new Macbooks and Macbook Pros utilise DDR3... and specifically at 1066MHz. I downloaded the manuals for both models and they specifically call for using DDR3 at that speed.

So.... if the chipset supports DDR3 @ 1333MHz, the questions that arise for me are:

1. technically, will DDR3 @ 1333 MHz work in the new machines?
2. if so, would there be any real-world performance increase?
3. if it works, why has there been no mention of it? If it doesn't work, why?

Hopefully someone has some insight into this... cheers!
 
mgpg89

mgpg89

macrumors 6502a
Aug 31, 2008
970
16
Belgium
abiyng87 said:
Not really sure what you are getting at here. Have you read the specs for the new macbooks? They come with 2GB (two 1GB SO-DIMMs) of 1066MHz DDR3 SDRAM.

Apple's Spec Page
Click to expand...

I'm guessing he'd like to buy some 1333MHz DDR3 RAM if this is supported in the new MacBook (Pro)'s and if there's a notable speed boost.

I'd like to know so too, actually ...
 
Sun Baked

Sun Baked

macrumors G5
May 19, 2002
14,937
157
Generally in the Macs, all the faster memory has done in the past is boost the chance that marginal cheap memory will work.

Putting faster memory just gets downclocked to the required speed.

The chipset might support 1333, but it currently is running at 1066.

---

If you want to hack EFI, and boost the memory speed, go ahead.
 
L

lwongveros

macrumors newbie
Original poster
Jun 15, 2007
26
1
Sun Baked said:
Generally in the Macs, all the faster memory has done in the past is boost the chance that marginal cheap memory will work.

Putting faster memory just gets downclocked to the required speed.

The chipset might support 1333, but it currently is running at 1066.

---

If you want to hack EFI, and boost the memory speed, go ahead.
Click to expand...

Sun Baked - thanks, I think I see how it works now... even though the chipset supports up to 1333MHz memory bus speed, in the Macbook it has been set to 1066 so installing DDR3 1333 (which I assume simply means its rated to run safely up to that clock speed) would be pointless and most likely a waste of money.

Cheers!
 
T

TPetersen

macrumors newbie
Aug 2, 2008
7
0
No they dont work, because there doesn't exists any 1333 MHz SO-DIMM 204 pin DDR 3 RAM.
1066 MHz is the fastest you get, you are looking at wrong RAMs, they will NOT fit your MacBook Pro.

You need to look after SO-DIMM 204 pin DDR3 RAM
 
T

TPetersen

macrumors newbie
Aug 2, 2008
7
0
Okay, i didnt know that, but they are not very good, the RAM timings on this ram is CL 9-9-9-24
Where the Kingston HyperX RAM is CL 5, and most of them are CL 7.
 
mlemonds

mlemonds

macrumors 65816
Apr 9, 2008
1,055
198
Lexington, KY
from what i could read on kingston's website, their hyperx for 1375mhz ram is 7-7-7-20. so the 9-9-9-24 that ocz is offering seems on par for the price difference. i guess that is why you pay soo much more for the hyperx ram. (also the hyperx uses a higher voltage)

The higher your bus speed the higher the latency times are going to be, but will still give you an overall faster experience.
 
bozz2006

bozz2006

macrumors 68030
Aug 24, 2007
2,530
0
Minnesota
I don't know much about this, so i'll throw it out there and let someone who actually knows about this stuff chime in; but doesn't the RAM kind of do double-time, so that as long as your RAM runs at half the clock speed of your FSB, faster RAM won't do anything for you????
 
T

Toofan

macrumors member
May 12, 2009
35
0
lwongveros said:
Hi everyone, I did a quick search on the forums and haven't seen anything regarding a doubt that I have....

We all know that the new Nvidia chipset being used in the new Macbooks and Macbook Pros utilise DDR3... and specifically at 1066MHz. I downloaded the manuals for both models and they specifically call for using DDR3 at that speed.

So.... if the chipset supports DDR3 @ 1333MHz, the questions that arise for me are:

1. technically, will DDR3 @ 1333 MHz work in the new machines?
2. if so, would there be any real-world performance increase?
3. if it works, why has there been no mention of it? If it doesn't work, why?

Hopefully someone has some insight into this... cheers!
Click to expand...

1) It depends, I wouldn't risk stability issues for the negligible 300 mhz
2) The word negligible in answer 1 should answer question 2
3) Try it out if you want, the fraction of time you'll be saving with increased RAM speed is laughably small
 
blackhand1001

blackhand1001

macrumors 68030
Jan 6, 2009
2,599
33
The cpu also only has a 1066 Front Side Bus, so i don't believe it will even run the memory at those speeds, and the even if it could, the front side bus is the bottleneck, not the ram itself.
 
K

keson

macrumors newbie
Sep 29, 2010
5
0
Early 2010 MBP 13" 1333 MHz RAM experience

Although late 2009 MBP 13" was running fine with Transcend 1333 MHz memory (2x4GB) when placed into early 2010 MBP 13" the same RAM does not work. MBP boots but freezes when starting loading kexts. No pram, nvram nor smc reset helped... It just can not run on 1333 :( Too bad.
 
A

akhbhaat

macrumors regular
Sep 30, 2010
127
0
With C2D-compatible chipsets, the memory clock is directly tied to the front side bus speed, which is in turn set against the CPU core multiplier to generate the CPU clock speed. You will see absolutely no benefit to pairing 1333 Mhz DDR3 with a CPU rated for 1066, provided said CPU is running at stock speeds. The bus (and the memory) will be set to run at 1066.

It's common practice for desktop system builders to buy uprated memory for systems that they intend to overclock, because manipulating the FSB speed is the most common way to manipulate the clock speed of a ratio-locked CPU (at least until the advent of the Core iX architecture, which is a bit different) and this will prevent the memory itself from being a stability concern, but I would think (and hope) that you wouldn't be so daft as to attempt overclocking in a laptop. The more notable consequences (additional heat and power consumption) are not acceptable for a mobile device. It also appears to require some significant hacking to pull off with a Mac anyhow.
 
P

Phil Brinkle

macrumors newbie
Apr 12, 2011
1
0
I would like to share a good solution how to force MacBook to work with DDR3-1333 memory modules. The problem is that the MacBook is not capable of supporting DDR3-1333 officially. But we can adjust the clock speed of the module through its SPD settings. Just download Thaiphoon Burner software, read SPD and then increase the SDRAM clock cycle time to 1,875 ns (15 MTB units) through the Timing Table Editor. And that's all! Now we've got a DDR3-1066 module which is full compatible with any MacBook.
 
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