Should I look at SPD when buying RAM?

[lukeman3000]

I recently bought some memory that was "tested" at 1600MHz but actually has an SPD of 1333MHz and must be tweaked either manually or by XMP to run at the advertised speed.

Is this normal, or did I get "duped" into buy slower RAM?

For reference, this was the Corsair Vengeance Low Profile 8GB (4GB x 2) on newegg.com.

Many users said they had to enable XMP to get the advertised speed of 1600MHz. Is this a nomral thing to have to do with RAM or should I try to buy 1600MHz SPD?

[Tradesman]

The 1333 is probably he default boot speed of your mobo if that's what it booted to or is the SPD default boot. Basically all DRAM 1600 and above will have a programmed 'default' boot set of timings. Most all current mobos, by default will boot to 1333 or 1600, because generally above 1600 it requires an OC of the CPU to run DRAM at the higher freqs - which is why you'll often see in mobo advertising they will list like:

1333, 1600, 1866 (OC), 2133 (OC), 2400 (OC)

the OC indicates that you require an OC of the CPU, this can be done manually or on an Intel mobo via XMP (if the BIOS is ready for it) or AMD uses DOCP (or a variant). You can identify the default freq for the sticks in CPU-Z by checking the SPD section under Max-Bandwidth (which is a very deceptive heading. So yes it's normal, and even if the default freq of the mobo is 1600, it's a good idea to use the XMP setting or manually set it, so you get the full performance from the sticks, you might have a set of 1600 spec at 8-8-8-24 but the mobo might default to 1600 and use slower 9-9-9-27 timings.

Can find more on my info thread here:

http://www.gskill.us/forum/showthread.php?t=10566

or an expanded version I wrote for BenchMarkReviews.com here:

http://benchmarkreviews.com/index.ph...20387&Itemid=8