24GB DDR3 and Windows 7

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Product: 2x Crucial 12GB (4GBx3) PC3-10600 Kit
Provided By: Crucial
Price: Find Lowest Price Online

 

Introduction:

It wasn't that long ago that 4GB of memory was a lot of RAM in a system and some crazy people were considering 8GB of memory for high-end 64-bit systems.  Recently, Crucial launched 4GB and 8GB memory modules that allow more people to be able to load up their systems for some serious multi-tasking applications.  We will be briefly looking at two pair of 12GB kits in our test system that gives us 24GB of memory to play with.  This is a pretty solid chunk of kit and it will currently set you back close to $1,000.  The interesting thing to see is if we can bog down a system and make it bleed.  We will be running a few benchmarks as well as some gaming while we have the system loaded in order to find the breaking point.

Packaged RAM
Packaged RAM

 

At my initial request for the memory, Crucial seemed quite excited to let us try and bog down a system, but somewhere in between the request and the shipment, they only shipped me 4x4GB of the DDR3.  They quickly made right on this by shipping a couple more sticks - but these didn't arrive in the same retail package.  The modules are the same model and specification though, so there should be no issues.

 Pile Of RAM
Pile Of RAM
Stack Of RAM
Stack Of RAM

 

Installation and Setup:

Although the motherboard we used for testing - the ASRock X58 Supercomputer, claims to be able to handle 24GB of DDR3, it's not as simple as plugging in the memory and having everything work properly.  By default the system would only detect 16GB of memory until we enabled the "Flexibility Option" in the BIOS.  When this was enabled we are now able to see all 24GB of memory.

24GB Installed
24GB Installed

 

CPU-Z shows the memory information and four possible JEDEC specifications that it can be clocked at.  For this article, we are simply trying out 24GB of memory in the system and left the RAM running at its default 9-9-9-25 at DDR3-1333.  As you can see, it has the ability to run a little faster at CL9 and quite a bit faster at CL10.  The performance you'll gain from the faster clock speed will be negligible though as you decrease the latency.

 

 CPU-Z

On the next page we'll start loading up the system and find out how much it can handle before we make it cry for mercy.


 

Loading Up The RAM:

As previously mentioned, most people cannot begin to use 24GB of memory in normal day-to-day activities.  Those using 3D modeling programs, working with large images in Photoshop or editing HD Video in Premiere can use large portions of memory, but the best way to really take up memory is to set up some virtual machines in VMWare and assign specific chunks of RAM to each OS.  In the VMWare screenshots below, we have assigned 1GB for Ubuntu, 3GB for Windows XP, and 8GB for each Windows Vista x64 and Windows 7 x64.  All were running background applications in order to load up their respective memory allotments and we took screenshots and ran benchmarks on the host Windows 7 Ultimate x64 OS.

 VMWare is a Killer
VMWare is a Killer
 One OS
One OS
 Three OS
Three OS

 

As you can see below, as each of the Operating Systems get installed and loaded up, the RAM usage increases.  The beautiful thing about having so much memory available on the Core i7 920 system is that each OS can be allotted a separate core and ample memory.  Once the VMWare is up and running, each OS is very responsive and works very quickly.  All this while still maintaining a very snappy and responsive host Operating System.  Once we have everything loaded up we are using a total of 21.1GB of memory - 20GB for VMWare systems and 1.1GB for the host OS - Windows 7 x64.

Four OS
Four OS

 

The incredible thing is that even when the system is loaded up with over 20GB of memory being used, and all of the VMWare clients being used to do some small tasks, the host system performance is still unwavering.  I ran some Call of Duty: Modern Warfare 2 without any load on the system and without VMWare loaded and I averaged 66 FPS during the "Loose Ends" mission where there is a lot of foliage, smoke and a lot of system intensive action.  When running VMWare and hogging over 21GB of memory, the game performance dropped down to 65 FPS as measured through FRAPS.  Of course this could easily be within margin of error, so the impact on system performance is really non-existent.  When running with 6GB or 12GB of memory, game loading times are super slow and the system slows to a crawl as the pagefile has to be written to and from the disk.


 

Benchmarking - Everest:

Because there is a lot of system tweaking that goes along with clocking up memory to non-standard speeds, we haven't included any "real-world" benchmarks.  In order to get the memory to run at speeds other than 1066MHz, 1333MHz, 1600MHz or 1866MHz the motherboard bus and CPU must be clocked up in order to achieve these speeds.  As we've shown before the CPU plays a huge roll in benchmark performance and so it's not fair to compare results when the CPU is clocked faster.  Of course the "RAM" will look faster, but in reality the CPU is the one doing the work.

For this reason we use two simply synthetic benchmarks to show memory performance.  How it affects performance in the real-world will depend largely on CPU, motherboard and other hardware bottlenecks so we have to be content with synthetic benchmarks to gain our number metric.  First up is Everest ran at the marketed CL9 settings.  We've included the results of a 1600MHz Ballistix Tracer Kit for reference.

Everest

 

As you can see above, the results between the two kits aren't radically different and performance looks very solid for the 24GB kit.  With that in mind, we'll take a look at SiSoft Sandra.

 

Benchmarking - SiSoft Sandra:

If you want to compare your triple-channel DDR3 performance, you can head on over and grab SiSoft Sandra here and compare away.  Please keep in mind that if you are using a dual-channel kit, your performance numbers will look dismal.

 SiSoft Bandwidth
SiSoft Bandwidth
 SiSoft Latency
SiSoft Latency

 

SiSoft tells a different story than Everest however.  The performance according to SiSoft is much lower on the 24GB system and this is why you cannot trust every synthetic benchmark.  One of these is true and the other is skewed.  The real results can only be measured in real-world performance and we've seen the system more responsive with massive loads on it with 24GB of memory.

 

Final Thoughts:

While this certainly hasn't meant to be a full review of a 24GB kit of memory, it is a bit of an eye-opener.  I never thought that I'd be able to load up a system and still be able to do everything I wanted to do - and do it fast.  Having 24GB of DDR3-1333 in this system enabled me to allot large amounts of RAM to each Virtual Machine in order to maximize the performance of each client - all while maintaining enough memory for the host Operating System to function at full capacity.  I was able to edit HD Video in Premiere, play games, use Photoshop and Lightroom to combine HDR photos, and still never suffered a slow-down due to running out of memory.  At times, I've had slow-downs with 6GB, but with 24GB, all these issues were gone.

Keep in mind that this large bundle of memory comes at quite an expense.  First, you'll have to be running a Core i7 system that supports six memory slots.  Second, you'll have to be able to spare an extra $1000 for the memory, and third - you should make sure that your motherboard is capable of running that much memory.  Finally, you'll obviously need to run a 64-bit OS so that you can address all that memory.  If you need 24GB of memory, it is possible without actually spending a fortune on RAM or a high-end server board.  That is good news.

We will have this memory for a little while longer so if you have any specific tests you'd like to see posted, please let us know.  All of your comments and feedback are welcome at the "Comments" link below.