Corsair Vengence 8GB LP or big headspreader?

elrasho · 31 Oct 2011 at 09:49

I have an AC Turbo 7 CPU cooler and so one of the memory modules is kind of covered by the giant fan. I want to upgrade to 8GB of RAM and so these: http://www.overclockers.co.uk/showproduct.php?prodid=MY-300-CS&groupid=701&catid=8&subcat=1517

I'm not sure of this RAM will fit. So I've been looking at the low profile ones but want to know as my i5 750 is overclocked to 3.7Ghz will the low profiles be able to run cool enough at their higher speed (I think its 1580Mhz).

elrasho · 31 Oct 2011 at 13:27

Dammit! Accidentally got the 1.65v instead of 1.5v

Could this be a problem for my i5 750 being overclocked to 3.7Ghz? Or are ram and CPU overclocks separate now? Will my motherboard (p7p755d pro) automatically lower the voltage to 1.5v?

elrasho · 31 Oct 2011 at 14:25

I bought this: CMX8GX3M2A1600C9

This is what I get for not buying from OCUK

EDIT: That Corsair website I linked to says: Tested Voltage 1.65 SPD Voltage 1.5, does that mean the memory runs at 1.5v but is capable of running at 1.65? They had the same RAM at 1.5v which was £2 cheaper so I think this may be the case.

elrasho · 31 Oct 2011 at 14:42

Surveyor said:
It's the same as this:

Corsair XMS3 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit

I have 16GB of that running at ~1.5V.

Those are blue where as the ones I linked to are black. Also will my motherboard (Asus P7P55D) automatically set the voltages to 1.5v or will I have to manually do it in the BIOS?

elrasho · 31 Oct 2011 at 14:49

Surveyor said:
Images are for illustration purposes only.

The RAM you've bought and the RAM sold by UK are exactly the same product.

Using the SPD settings will default to 1333MHz @ 1.5V.

Using the XMP profile will default to 1600MHz @ 1.65V.

So you want to manually set 1600MHz and ~1.5V.

Thanks mate

Will give this a go tonight. I don't understand why these 1.65v ones exist? If you can run 1600Mhz at 1.5V why would you want to run the same speed at higher volts?

elrasho · 31 Oct 2011 at 17:43

Put in the 1.65V ram and my mobo defaulted to 1.65v. I manually changed it to 1.5V and its still working

Cpu-z shows the same values as my old 4GB ram did in terms of 9-9-9-24 and it running at 782Mhz (times by two is 1564Mhz which I think is 1600Mhz but CPU-Z doesn't measure it accurately). Thanks for all your help Surveyor

elrasho · 31 Oct 2011 at 19:54

I disabled CPU Spread Spectrum (couldn't see a DRAM Spread Spectrum) but the ram is still running at 1564Mhz. In the BIOS DRAM frequency seems to be set to 1564Mhz, the other values are 1950Mhz and 1780Mhz. I can't seem to edit this to 1600Mhz.

EDIT: It appears the BLCK frequency determines the RAM speed. I'm scared to make it higher in case it fires my CPU/Board.

According to CPU-Z I should be running the ram at 1.65V as it showd 1600Mhz running at this voltage... I'm confused

elrasho · 31 Oct 2011 at 21:32

Surveyor said:
Why be confused?

As I said earlier that's the voltage they test it at and use in the XMP profile but in practice it will run at lower voltage.

If you've set 1.5V and it's running fine then you have nothing to worry about.

OK cool, I can get a bit anal about my rig. Spent a lot of time and money building her just the way I want. Thanks again mate, your a real asset to these boards

elrasho · 31 Oct 2011 at 22:53

Surveyor said:
Thank you for the kind comments.

I hope you enjoy the upgrade

I certainly am! Loaded up BF3 and noticed I'm only using 1600MB of VRAM where as before the RAM upgrade it was 1950MB. So I increased some settings to Ultra and the FPS has stayed the same more or else. But the best thing is the stuttering has gone!

The only think I can think of is the extra RAM has allowed the game to buffer the textures and so I no longer run out of VRAM