The 512mb Tests

The first tests I ran were designed to see if the number of installed DIMMs made any difference when it came to 4-way interleaving. I also wanted to be sure to isolate the amount of physical memory to make sure that it was consistent across all tests. To accomplish this, I settled on a physical memory size of 512mb. This made it easier to test because I could use four 128mb DIMMs, two 256mb DIMMs, and a single 512mb DIMM. Therefore the only thing actually changing from run to run was the number of DIMMs installed.

I also wanted to verify that the interleaving was indeed running as it was supposed to be, so before running any tests I checked Sandra's "Motherboard Info". If you scroll down a bit in the results, you will see something like this:

The above image shows what you would see with four 256mb DIMMs installed (two 128mb banks per DIMM). We can indeed see that the memory speed is 134mhz and that 4-way interleaving is enabled. Also note that our memory timings are set pretty aggressively (2-2-2) which proves that George's Memory Interleave Enabler is doing its job. Cool... Everything looks in order, let's move on.

SiSoft Sandra - Memory Bench

Corsair CM654S512LP-133 ( x1 )


Corsair CM654S256-150C2 ( x2 )


Corsair CM654S128LP-133 ( x4 )

WOW! How depressing! Sandra is showing absolutely no improvements no matter the number or size of the DIMMs installed. Man... I was hoping to see something change. Maybe CliBench will tell another tale. Let's take a look:

CliBench Mk III SMP 0.7.10 - 512mb Tests
	128 x 4	256 x 2	512 x 1
Dhrystone 2.1	2573	2573	2573	MIPS
Whetstone	869	869	869	MFLOPS
Eight Queens Problem	3404	3404	3413	pps
Matrix Operations	73972	74342	75500	k ops
Number Crunch	119349	119349	119410	k ops
Floating Point	11902	11902	11891	k ops
Memory Throughput	151920	151920	151920	kB/sec

Newp... Same story here. I guess we can make some pretty good conclusions about the affect of DIMM size and quantity when using 4-way interleaving. Well, ummm, there are no benefits to having multiple DIMMs installed. I guess the old overclocker's motto "One big stick is better than multiple smaller ones" could apply here. On the other hand, if you already have a few smaller DIMMs installed, you shouldn't worry about the addition of another DIMM or two affecting your memory performance.

Looks like a total wash to me... Let's try something else.