Does X220 Support 1866MHz Ram?

[whitelabel]

Hi!

I'm curious about the real benefits from using 1600/1866 MHz RAM. Are there any? I assume no.
Intel's datasheet for i7-2620M says that this CPU supports only DDR3 1066/1333
(Check Memory Specifications here: http://ark.intel.com/products/52231/Int ... apkw=2620m)
So, what's the real deal with it?

p.s.
I got 16GB of 1333 MHz RAM and i7-2620M and it works great. However I never tried 1600 or 1866 RAM.
Also I've been able to find modified BIOS 1.40 with memory support range unlocked. And I'm wondering why Lenovo
has limited this range to 1066/1333 in the newest BIOS versions while old versions (as people say) had supported
1066/1333/1600/1866 MHz RAM). So why Lenovo has enabled all four frequencies in the first place? And why Intel says
that only two modes are supported? Some strange stuff here.

Thanks!

[johnmcdonnell]

I have an x220 with a 2.6GHz i5-2540M CPU and 16GB of DDR3 1866 Crucial Ballistix Sport RAM. The BIOS is a modified version of 1.40 with adjustable RAM speeds. Ran a couple quick benchmarks using PC Benchmark from Jujuba Software.

Memory set to 1333MHz gave these results:
- GPU Compute: 162.01 speed ops
- Main RAM: 1,875.20 MB/s

Memory set to 1866MHz gave these results:
- GPU Compute: 174.98 speed ops
- Main RAM: 2,329.60 MB/s

Pretty decent improvement in memory speed and some modest gains in GPU performance. Can't say I really notice any difference with day-to-day use, though.

Edit: Ran some additional benchmarks with PerformanceTest 8.0 - red is 1333MHz, green is 1866MHz:

[whitelabel]

Hey johnmcdonnell!

So its possible to use the RAM at 1866 speed after all. Thank you for confirming this and for the benchmark results!
It's very useful and much appreciated!

I think you might notice the difference between 1333 and 1866 in some heavy apps.