Overclocked MSI 865PE-Neo and DDR Memory Bandwidth

[Mr Incredible]

I recently completed a project to allow my MSI 865PE-Neo2-S motherboard to be overclocked to the max possible by swappin gout my old CPU (2.8 Nprthwood 533FSB) for an eminently clockable 2.4C on 800FSB.

I bought some OCZ PC4400 (DDR550) 2 x 512MB DIMMS as reviewed and tested here:

[Tweaknews] - OCZ 1GB PC4400 DDR550 PERFORMANCE SERIES DUAL CHANNEL MEMORY KIT REVIEW - Page 6

Note the Sandra soft Memory Bandwidth of the Dimms is over 6000 MB/s

The bandwith of the COrsair PC3200 was 4800 MB/s.

This is what my system look likes...

But Sandra Memory Bandwidth looks like this:

SiSoftware Sandra

Int Buffered iSSE2 (Integer STREAM) Results Breakdown
Assignment : 4062MB/s
Scaling : 4058MB/s
Addition : 4050MB/s
Triad : 4109MB/s
Data Item Size : 16-bytes
Buffering Used : Yes
Offset Displacement Used : Yes
Bandwidth Efficiency : 47% (estimated)

Float Buffered iSSE2 (Float STREAM) Results Breakdown
Assignment : 4128MB/s
Scaling : 4113MB/s
Addition : 4140MB/s
Triad : 4206MB/s
Data Item Size : 16-bytes
Buffering Used : Yes
Offset Displacement Used : Yes
Bandwidth Efficiency : 48% (estimated)

Test Status
Device Type : Desktop
Memory Used by Test : 512MB
NUMA Support : No
SMP Test : No
Total Test Threads : 1
SMT Test : Yes
Number of Test SMT (per CPU) : 2
Dynamic MP/MT Load Balance : No
Processor Affinity : No

Chipset 1
Model : Micro-Star International Co Ltd (MSI) 82865G/PE/P, 82848P DRAM Controller / Host-Hub Interface
Front Side Bus Speed : 4x 272MHz (1088MHz data rate)
Width : 64-bit
Maximum Bus Bandwidth : 8704MB/s (estimated)

Logical/Chipset 1 Memory Banks
Bank 0 : 512MB DDR-SDRAM 3.0-4-4-8CL 1CMD
Bank 1 : 512MB DDR-SDRAM 3.0-4-4-8CL 1CMD
Channels : 2
Speed : 2x 272MHz (544MHz data rate)
Width : 64-bit
Performance Acceleration Technology : No
Maximum Memory Bus Bandwidth : 8704MB/s (estimated)

Features
MMX Technology : Yes
SSE Technology : Yes
SSE2 Technology : Yes
SSE3 Technology : No
HTT - Hyper-Threading Technology : Yes

Performance Tips
Notice 5008 : To change benchmarks, click Options.
Notice 5004 : Synthetic benchmark. May not tally with 'real-life' performance.
Notice 5006 : Only compare the results with ones obtained using the same version!
Warning 5400 : Low bandwidth efficiency (advanced). Check memory timings and settings.
Tip 10 : To benchmark/test your PDA / SmartPhone, use the 'Switch Test System' button.
Tip 2 : Double-click tip or press Enter while a tip is selected for more information about the tip.

The SPD on the CPUID states a timing of 3-6-6-12 for 275MHz

and yet the reported timing is 3-4-4-8 when at 272MHz. In the BIOS I cannot relax the timings at all. I have them installed on Slots 1 aqnd 3 in the DIMM slots. Bios reports Dual Channel - Liner Mode (whatever that is!)

Anyone have any ides why I am getting just 48% bandwidth efficiency?

I am very

[Mr Incredible]

I cannot understand why my rated memory running at a rated DDR544 is marginal compared to DDR400 (albeit on slightly tighter timing).

[Mr Incredible]

I think I may have found a reasonable explanation in this test of some Corsair PC4400 (DDR550) memory....

Corsair TWINX 1024-4400

Looks like my chipset is the limiting factor. With the same memory and speed, the Canterwood chipset raised the memory bandwidth of the Springdale up to 6400 MB/s. Grrrr..

Looks like I am limited my my MOBO even though it can clock right up to 299MHz if pushed!

Oh well, I think I've sussed out the problem.