Ram Setup, 2 different speeds

Hey all,

Well I'm having issues with getting my RAM speeds up to where they should be. Im new with this kinda of stuff so please bare with me. I will list my specs of my system then explain my issue.

CPU - Intel i5 750 Lynnfield Core

Motherboard - Asus P7p55 LX

Ram - 8GB G-Skill Ripjaws DDR3 1600 (PC12800)

So I bought 4 GB of that ram back when I bought this CPU and MB. I really never knew about setting up the speeds or anything. I recently bought 4 more GB of the exact same ram, and learned a bit on setting up speeds and such in my bios.

I cant seem to get the speed up to 1600MHz.

I look on CPU-Z and slot 1&3 show Max Bandwidth PC3-12800H (800MHZ)
Here is a Screenshot of what slot 1&3 show on CPU-Z

Slot 2&4 on CPU-Z show Max Bandwidth PC3-10700 (667MHZ)
Here is a screenshot of what 2&4 show on CPU-Z

I tried to manually set it up in bios to run 1600MHZ and also tried to run X.M.P Profile which sets up all the setting automatically and it changes nothing. Does my CPU only allow 1333? Im a bit confused on all this. Also i read that CPU-Z will only show it running at 800MHZ because its Dual Channel so it cuts it in half? but its really running at 1600MHZ.. Also why are 1&3# slot running different speeds than 2&4? Any help with be great!!!!

If you have any questions I would be glad to get you all that info!
9 answers Last reply
More about setup speeds
  1. If you click on the MEMORY TAB it will show you the actual timings the RAM is running at. The SPD Tab shows you the options for the RAM.

    It looks like you are reading Maximum Band Width not the actual RAM frequency which if set for the XMS Profile would be 800 Mhz. x 2 = 1600 Mhz. Double Data Rate RAM, (DDR) runs at twice the specified clockspeed frequency so 2x 800 for 1600 actual system RAM speed.

    It looks like your RAM is running at 1600 Mhz. in all slots. Max Bandwidth is what the RAM is rated at not the frequency it is currently running. The XMP profile to the right bottom is the frequency and timings that the RAM is using when you select the XMP profile.
  2. Why is slot 2&4 different than 1&3 for max Bandwidth?
  3. Because the RAM you have in those two slots is a different model RAM than in slots 1 & 3. One set is PC3-10700 and the other set is PC3-12800 spec. The higher frequency gives you slightly more bandwidth.
  4. Its the exact same part number and same ram I ordered right from newegg.
  5. That may be true but without it being ONE matched, tested RAM kit, the DIMMs can be programmed differently in SPD - which is what is being read. This even happens some times in matched kits. I've even seen DIMMs with the same part number that had different chips on the DIMM even thought the part number was the same.
  6. just return those 2 sticks and get new ones?
  7. Returning the RAM sticks won't change anything if the RAM is running fine in XMP @ 1600 Mhz. Geesh.
  8. chill man, i was talking about the ones at pc10700? or they are all working fine?
  9. What is the point of returning the DIMMs if they function properly?
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