What is XMP?

[Carson Dyle]

I'm putting together a system with an i5-3750k on an ASUS P8Z77-M Pro motherboard and trying to figure out which 2x4GB DDR3 1600 memory to get. I have no criteria other than wanting to stay away from tall heatsinks. The memory won't be overclocked.

I'm reading a lot of Newegg reviews of different memory stating that the user's motherboard didn't recognize it at the spec'd speed or timings. Some reviewers mention having to run the memory in XMP mode or having to manually set timings in the BIOS just to get the manufacturer's claimed speeds. I'd like to avoid this. I'd prefer it simply work with no hassles and not feel liking I'm tweaking the system to get the memory to run as expected out of the box.

 

[ShintaiDK]

XMP=eXteme Memory Profile.

You cant avoid it so to say to run at those speeds. My own memory only runs 1333 at SPD speed, and 1600 at XMP speed.

 

[Carson Dyle]

Thanks.

Why can't it be avoided? I thought Ivy Bridge supported DDR 1600 as standard.

 

[ShintaiDK]

Thanks.

Why can't it be avoided? I thought Ivy Bridge supported DDR 1600 as standard.

It does support 1600Mhz. But you need memory with actual 1600Mhz SPD speed to get IB to run at 1600Mhz. Or use the XMP on 1333Mhz SPD memory with 1600Mhz XMP option.

Example:
http://www.gskill.com/products.php?index=482

 

[Carson Dyle]

So you're saying that RAM sold as DDR 1600 is actually programmed in SPD to be recognized as 1333? Why wouldn't they just change the SPD programming, or would it create a problem running it in systems that only support 1333?

 

[ShintaiDK]

So you're saying that RAM sold as DDR 1600 is actually programmed in SPD to be recognized as 1333? Why wouldn't they just change the SPD programming, or would it create a problem running it in systems that only support 1333?

Yes thats what I am saying.

Why? I guess it relaxes quality abit, since XMP is considered an overclocking profile. In other words, I dont think those memory modules could pass 1600Mhz SPD.

 

[WilliamM2]

So you're saying that RAM sold as DDR 1600 is actually programmed in SPD to be recognized as 1333? Why wouldn't they just change the SPD programming, or would it create a problem running it in systems that only support 1333?

I think it depends on the memory, and the motherboard. I use this memory, http://www.gskill.com/products.php?index=390 , on an Asrock P67 Performance board. It's correctly recognized as 1600 with or without XMP. The only thing selecting XMP does is lower tras from 28 to 24.

 

[ShintaiDK]

It depends alot. You got 1600Mhz SPD speed. Some dont. Its a consumer nightmare and wierd how it can be legal. Since those with 1333Mhz SPD is essentially false marketing.

 

[corkyg]

Different definitions are really confusing. In my book, XMP-Extensible Metadata Platform.

http://en.wikipedia.org/wiki/Extensible_Metadata_Platform

 

[Carson Dyle]

It does look like DDR 1600 SPD modules do exist, but they're few and far between.

Looking at the ASUS memory QVL for the P8Z77-M Pro (PDF file), nearly all of the qualified DDR 1600 parts are listed with "XMP" in parenthesis, but a handful are not. One of those is Kingston's HyperX Genesis PnP 8GB kit KHX1600C9D3P1K2/8G. No doubt the PnP designation reflects the SPD programming, and Kingston's product page states:

"Increase speed without manually changing system settings — PnP is preset for maximum speeds and easy to install."

A little pricier, but with a $15 rebate, same as most other inexpensive DDR 1600 2x4GB kits:

http://www.newegg.com/Product/Produc...82E16820104255

 

[bryanl]

It does look like DDR 1600 SPD modules do exist, but they're few and far between.

If you mean DDR3, here are some, unfortunately only 4GB per DIMM:

http://www.newegg.com/Product/Produc...82E16820147096