RAM on a MBP - quantity vs speed

I currently have 8 GB of DDR3-1333 on my 2011 MBP. I know these systems can accept both 1600 MHz RAM as well as 16 GB of the stuff. I can't seem to find an answer as to what would deliver the biggest performance boost for general productivity, with some gaming on both the Windows and OS X side. Now 16 GB of DDR3-1600 would be ideal, but that doesn't exist (yet) and would certainly be cost prohibitive.

I only run a single VM, and that's my Win 7 Boot Camp install through Parallels 7. It currently has 2 GB assigned to it, which seems to work OK because I only really use it for MS Office and playing the original Half-Life games, both of which run perfectly fine as-is.

Take price out of the equation, which would offer the biggest benefit?

 

I've always heard that speed doesn't matter much.

 

except for benchmarking bragging rights. I say go with more, the downside is many general apps dont seem to take advantage of it, I dont run vm's so cant comment much there.

biggest benifit depends on the apps you run and how heavily, if your just running pages, safari etc neither will boost it much, an SSD would give a more noticeable increase

 

definitely making sure you have enough quantity to meet memory demand is far and away the most important thing. the relatively minor differences in memory speed hardly make a difference.

of course, with 8 GB of memory, you're probably already able to meet that demand, and it's very likely that adding more memory will not make any difference, given your use. The other components (specifically your CPU, GPU, and HDD) are all much more relevant to system performance. I would say the only way to get any performance benefit at your point would be to get an SSD.

you can also run the activity monitor. upgrading memory is prudent only if these conditions are met:

1. free memory + inactive memory is close to 0.
2. page outs is growing rapidly while you watch it, especially if page ins is also growing at the same time.

Having page outs is fine, and page ins is perfectly normal (loading data from HDD) but ideally the system shouldn't need to page out very often, and shouldn't have to trade paging out with paging in.

 

The speed increase isn't going to be noticed more than the amount of ram to be used, the higher capacity ram will give you a bigger boots overall for sure, the speed increase is just a matter of 1-2% boost, while more ram is a huge factor..


It doesn't really matter if the free memory is close to 0 or not, because usually OSX will figure things out and free up so you will never see if you're bottoming out the memory usage besides in rare cases. So it will not always give you a true value, usually when you stuff more ram into the laptop it will also make use of the more memory instead of conserving and sharing it with the small amount you had before. So even if masterchef341 has a point in what he says, that is not always the case..


I've written a whole FAQ about DDR memory btw..



A SSD will for sure give you a big performance boost no matter what system you got, loading times are ALOT faster for everything and in general always gonna be faster. So the best investment is getting a SSD imho.

 

I kind of figured this would be the case. There wasn't a whole lot of need to upgrade, as the set I have right now only cost $30 and does the job just fine.

Unfortunately, an SSD isn't feasible. For the money, I'd be looking at a 256 GB model, which isn't enough space for all the stuff I have on both the Windows and OS X side. I also use the optical drive so it's not an option to remove it and put the old HDD in a caddy.

I've actually been pleasantly surprised by the responsiveness of the standard 750 GB hard drive. For 5400 RPM it's reasonably quick, not to mention silent and vibration free. I initially planned to replace it with my old WD Scorpio Black, but that's not going to be necessary. The only time when the slower speed is really painful is when installing large system updates. When OS X 10.7.3 dropped a little while ago, it took quite a long time to get it fully installed. Other than that, it's more than adequate for my needs, and I appreciate all the extra storage capacity.

 

Well, it doesn't need to be exactly zero, it just needs to be low "enough" - at some point you'll start seeing the page outs and page ins happening rapidly at the same time. That is OS X trying to swap memory in and out to prevent bottoming out completely. That could affect performance for sure.

With 8GB of ram, this isn't likely to be common issue.

 

I agree, you are absolutely right!

 

I just ordered 16GB of 1600Mhz RAM from Newegg over the weekend.
Newegg.com - CORSAIR Vengeance 16GB (2 x 8G) 204-Pin DDR3 SO-DIMM DDR3 1600 (PC3 12800) Laptop Memory Model CMSX16GX3M2A1600C10

Not a big price jump from the 1333Mhz modules ($20-$40 depending on brand/series).

 

indeed. I would ask why, but... nevermind.

Did you read the thread or just post here?

 

I read the thread, he specifically said he couldn't find something so I was just pointing out where he could find it.

I realize the main question of his was more RAM or speed which was already clearly answered by you and others so I didn't comment on that.

From original post:

 

I see. Indeed.

 

Heh.

 

Just to make it clear, you still run at 1333Mhz? And they are out of stock BTW

 

Nope, MBP runs the RAM at their rated clock. The 1866Mhz shows 1866 in "About this Mac" and the 1600Mhz currently shows 1600Mhz.

EDIT:
Specifically the MBP from late 2011.

 

The 2.2 GHz and above Core i7 15-inch systems from early 2011 can do this as well.

 

Benchmarks provide only 1-3% (at most) improvement from going with faster RAM (however in real-world usage, many people on this forum will swear that they feel a >1-3% performance improvement from overclocking RAM/upgrading 1333 to 1600/etc.), but as said before your system is only as fast as its weakest link (which 90% of the time nowadays is a mechanical drive). 8GB seems to be the sweet spot for performance gains under "normal" use, anything above that it pretty much plateaus and is really only going to give you better performance if you do A LOT of multitasking.

 

4 GB is actually plenty for performance. The main attractor for 8 GB is that the price of memory has dropped enough to make it cheap.

 

I certainly can't tell the difference between 1333, 1600 or 1866 in terms of performance. I figure if the price difference is only 20 dollar or so, why not though.

As for max memory, with caching (at least on Windows 7), 8GB seems like a good amount - 6GB really but due to dual channel, 8GB.

For me, I run a lot of VMs, which eat up 8GB of RAM off the bat - minimum. That's why I picked up 16GB.

 

I didn't actually know this. Thank you for the information. I think I'll stick with the 4GB actually, and update to 16GB in summer instead of 8GB now... I don't use it, just to have it... Say whatever you want..