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Improvement from 4GB memory to 8GB?

M

montblanc1

macrumors member
Original poster
Jun 18, 2009
95
0
Will the improvement from 4GB memory to 8GB be significant? I will replace my SATA HDD hard disk with intel SSD definitely, but I am just curious about the performance the extra 4GB will bring me!!!
Also, my current cpu is intel core i 5 2.4ghz model, will this cpu fully support 8GB memory, that's to say, will cpu limit the performace of 8GB ram? Thx
 
Depends what you do with it. If you're getting a lot page outs, you will need more RAM.

Yes, your CPU can fully support and utilize 8GB
 
you'd probably want to run the 64bit kernel, makes ram usage a little more efficient above 3GB.
I have 8GB and I love it. Of course I don't have a SSD so the performance increase is far greater for me, as I can store more apps in the ram, with out having to load them from the disk again.
 
8 Gb RAM -> WOW!

I did this upgrade a few months ago, and wow, things are faster. I also have a 160 Intel G2, and the speed improvement is really noticeable. I can now run a virtual machine without any slowdown at all. I think it's totally worth the upgrade if you can find a decent price.
 
mulo said:
you'd probably want to run the 64bit kernel, makes ram usage a little more efficient above 3GB.
I have 8GB and I love it. Of course I don't have a SSD so the performance increase is far greater for me, as I can store more apps in the ram, with out having to load them from the disk again.
Click to expand...

32-bit kernel can utilize up to 32GB of RAM, there is no need to run 64-bit kernel.
 
uller6 said:
I did this upgrade a few months ago, and wow, things are faster. I also have a 160 Intel G2, and the speed improvement is really noticeable. I can now run a virtual machine without any slowdown at all. I think it's totally worth the upgrade if you can find a decent price.
Click to expand...

What laptop ram do you recommend for macbook pro? I've seen a tons of rams (2*4GB)in newegg.com, price ranges from $140 to more than $300. All that I know now, is macbook pro's cpu only support 1067MHz, so I don't need to waste money on 1333 one. But to my surprise, some 1333 one is even cheaper than 1067 one, so how can I determine which is ram superior one?
 
Hellhammer said:
32-bit kernel can utilize up to 32GB of RAM, there is no need to run 64-bit kernel.
Click to expand...

nope, the apps can address up to 32GB, the kernel is stuck at 3GB. Doesn't matter too much in mac, not like in windows where the kernel takes care of ram management, hence "makes ram usage a little more efficient"
 
What kind of Page out/in and Swap stats should we be looking for when deciding about whether or not we need to upgrade our ram? Right now I'm sitting at 8mb/128mb swap, and 85,438 Page ins and 97 page outs.
 
Hellhammer said:
32-bit kernel can utilize up to 32GB of RAM, there is no need to run 64-bit kernel.
Click to expand...

Hammer, is it possible for apple to implement the 64 bit kernel in the future through an update or new OS (on startup, permanently)? Or is this something we'll need to do manually?
 
Blu101 said:
Hammer, is it possible for apple to implement the 64 bit kernel in the future through an update or new OS (on startup, permanently)? Or is this something we'll need to do manually?
Click to expand...

2010 Mac Pros boot into 64-bit kernel by default. I think the issue is that not all kexts/drivers in all Macs support 64-bit kernel so Apple would have to update them to 64-bit in order to make all Macs boot into 64-bit. Some kexts seem to be 32-bit as most Macs boot into 32-bit be default.

So yes, Apple could make all Macs with 64-bit CPUs to boot into 64-bit kernel if all other things supported 64-bit. Lion may have only 64-bit kernel, nobody knows.

And yes, you can do it manually if you want to.

I'm not a software specialist though so I'm not 100% sure about this 64-bit kernel scheme.
 
Hellhammer said:
2010 Mac Pros boot into 64-bit kernel by default. I think the issue is that not all kexts/drivers in all Macs support 64-bit kernel so Apple would have to update them to 64-bit in order to make all Macs boot into 64-bit. Some kexts seem to be 32-bit as most Macs boot into 32-bit be default.

So yes, Apple could make all Macs with 64-bit CPUs to boot into 64-bit kernel if all other things supported 64-bit. Lion may have only 64-bit kernel, nobody knows.

And yes, you can do it manually if you want to.

I'm not a software specialist though so I'm not 100% sure about this 64-bit kernel scheme.
Click to expand...

Cool. I was thinking of this thread:

https://forums.macrumors.com/threads/1034905/

I think mine boots in 32 bit mode, but I don't want to mess with it. Not yet at least. I'd rather wait for apple to pull the switch, if they ever plan to.
 
Ok, some 64 bit / 32 bit info. If you would like to see your intel based mac running on the 64 bit kernel, just reboot and hold down <option> 6 and 4 keys. (yes, that is the numbers 6 and 4 for "64") no joke.

This can be set as the permanent boot mode if you like through plist updates on the command line. mroogle will find them for you.

As for the "addressable" memory by the kernel... technically, a 32 bit data bus can address up to 4GB of storage (this is true GB as opposed to disk based gb) However, keep in mind you are running 2 cores at 32 bit each... thus, 8Gb.
 
mulo said:
nope, the apps can address up to 32GB, the kernel is stuck at 3GB...
Click to expand...

This is from another thread of mine:

toxic said:
the 32-bit kernel is not limited to 3GB. it uses PAE, so it can address up to something like 16GB.
Click to expand...

And from the thread I posted above:

Transporteur said:
The 4GB memory limit applies for a true 32bit system, that's true.
The Intel architecture the Mac uses, however, uses a nifty little thing called PAE (physical address extensions), which allow the system to address 36-bit addresses. This is the reason that even 32bit kernel Macs can address more than 4GB of RAM. Actually the limit would the 64GB, Apple limits it to 32GB though, which makes the 64bit kernel mandatory for memory sizes of 32GB+ (only available for Mac Pros atm).
Click to expand...
 
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