Changing Base Clock Effect On Memory?

[A Guy]

Hello all, 1st post here, and doing some research for my new PC. Here is my current setup:

ANTEC Three Hundred Illusion Black Mid-Tower Case, ATX, No PSU
ANTEC TruePower New TP-550, 80 PLUS®, 550W, 24-pin ATX12V EPS12V, One 6-pin + One 8-pin PCIe, SLI Certified
ASUS P7P55D, LGA1156, Intel® P55, DDR3-2133 (O.C.) 16GB /4, PCIe x16 CF /2, SATA 3 Gb/s RAID 5 /7, HDA, GbLAN, FW /2, ATX, Retail
INTEL Core™ i5-750 Quad-Core 2.66GHz, LGA1156, 4.8 GT/s, 8MB L3 Cache, 45nm, 95W, EM64T EIST VT XD, Retail
COOLER MASTER Hyper 212 Plus CPU Cooler, Socket 1366/1156/775/AM3/AM2, Copper/Aluminum, Retail
KINGSTON 4GB (2 x 2GB) HyperX PC3-10600 DDR3 1333MHz CL7 (7-7-7) 1.65V SDRAM DIMM, Non-ECC
EVGA GeForce® 9500GT DDR2 550MHz, 1GB GDDR2 800MHz, PCIe x16 SLI, VGA+DVI, HDTV-Out, Retail
SEAGATE 320GB Barracuda® 7200.12, SATA 3 Gb/s, 7200 RPM, 16MB cache
SEAGATE 320GB Barracuda® 7200.12, SATA 3 Gb/s, 7200 RPM, 16MB cache
LG ELECTRONICS GH24NS50 Black 24x DVD±R/RW Dual-Layer Burner, SATA, OEM
Windows 7 Home Premium 64Bit

Mind, I do not game or do extensive video editing, etc. this is my new, overkill PC for my daily internet use, video, etc. I've done a great deal of research on the individual parts, and the combination, and I'm happy with this setup, but I have a question.

When reading this article:

Efficiency Explored: What's The Perfect Clock Rate For Your Core i5?

http://www.tomshardware.com/reviews/core-i5-750-efficiency,2500.html

It becomes clear that with just changing the base clock to 160, I can achieve a reasonable overclock with the 2 turbo modes, while retaining the power efficiency overall, and at idle. This seems a good choice for my usage:

"Moving from a 133 MHz BCLK to 150 or 160 MHz, which was the maximum setting in our tests that didn’t require a voltage increase, does not increase your total system idle power. Apparently, the processor power saving features keep idle power in check very efficiently. Peak power, which would be our top reason against high overclocks, still doesn’t explode. We measured less than a 6% increase in peak power on the MSI P55-GD65 when going from a 133 to 160 MHz clock. This had the processor reaching 3.36/3.84 GHz maximum clock speeds in the two applicable Turbo Boost modes (one to two and three to four cores used)."

My question is, what effect (good or bad, if any) will this have on my memory performance specifically, and my overall system in general? Does changing just the base clock in this manner affect memory at all? I'd be looking for the most bang for my buck, without sacrificing power consumption overall, and taking advantage of turbo and the power savings functions. This seems ideal. Any feedback from all the experienced users here would be appreciated. A Guy

 

[jclw]

Memory clock is derived from the Base clock, so yes - it would effect it.

1st of all - DDR memory actaully runs at half of what it is advertised at. So your DDR3-1333 actaully runs at 666mhz. Because it is "Double Data Rate - DDR", the marketing guys just figure they'll call it "1333" instead of "666" because bigger numbers sell.

There are only certain "multiplers" that can be combined with Bclk to create memory speeds. I'm not sure off the top of my head which multipliers are available with the i5-750 but for example lets say you have x4, x5, x6, and x7 available.

Normally with 133mhz Bclk, and DDR3-1333 (666mhz), you'd run a x5 memory multiplier, giving you 133 x5 = 666mhz.

At 160 Bclk, you'd be trying to run your memory at 160 x5 = 800mhz (DDR3-1600).

So you have two options:
1) Set your memory multiplier to 4x so you run 160 x4 = 640mhz (DDR3-1280);
2) Buy DDR3-1600.

I'd go with #2 - DDR3-1600 is cheap.

 

[A Guy]

Thanks for the reply jclw. It looks like the 1600 is about $14 more. But will I notice much difference between 1333 running at 1280, and 1600 running at 1600? Will the difference between the 1333's CL7-7-7, and the 1600's CL8-8-8 be negated by running at 1600? I'm likely to get the 1600 since my clock of 160 will suit my CPU, and it looks like the i5's multiplier is 5 (or 10) by default. If this is so, just changing the base clock to 160 will again be perfect for my CPU and Memory. Thanks again, A Guy

 

[jclw]

As a simple comparison: 1600 is 25% larger then 1280, but 7 is only 12.5% faster then 8.

 

[A Guy]

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