Thinkpads Forum

Just replace the 2x2Gb PC3 10600 DIMMS with 2x4Gb PC3 12800 DIMMS in my T420. The Windows Experience Index for memory, CPU and both graphics metrics decreased significantly (1.0 or more). While I know that the windows experience index is not the last word in performance metrics, we're comparing apple to apples here and the bigger, faster apples appear to have hurt performance.

Any thoughts?

Run a few memory benchmarks with the old and new RAM and report your findings.

Unfortunately, the old RAM is gone.

Did you run it just before and after the change? Did you only run only the Windows Experience Index? Different benchmarks with more concrete results would be a lot easier to compare. Windows Experience Index is fraught with issues and I ignore it because I've seen it say lots of silly things, but I can't think of any good reason for it to have decreased if the only difference was the increase in RAM capacity. My gut instinct is to say just ignore it. Also have you checked that everything is running at full speed? Download a program called CPU-Z, and make sure that the CPU and RAM are at their top speeds when you run the Windows Experience Index tests. If the system checks out as being fine and Windows Experience Index is still giving you guff, just ignore it.

Edit:
I just ran Windows Experience Index on my computer. I guess I ran it once when I first got it, and it said I needed to run it again. It went from 4GB to 8GB and from a T9400 to a T9900, with everything else being the same. The CPU score went up, but the memory and graphics performance went down. Just ignore that junk. No real benchmark is going to be able to test the CPU, GPU, RAM, and HDD in three minutes and give you any meaningful information.