Problems? See this thread at archive.org.
This guide is meant to help get the RAM running at speeds above 1866MHz on AW18 R1 - since the laptop doesn't detect SPD timings / clocks beyond 1866MHz regardless of what the modules are actually rated at, the timings and ratios have to be input manually.
This is on the A10 BIOS, with 4x8GB Corsair 2133MHz modules. Make sure that your modules support whatever clock speed you are trying to reach - overclocking is possible, but difficult since the voltages are locked.
Disclaimer: I am NOT responsible for any damage to your system that may result from following this guide. Stick to the SPDs as much as possible, and proceed at your own risk.
1. Get a software that shows you the SPD timings - most software will show you only the basic clocks (tCL-tRCD-tRP-tRAS), but since the BIOS doesn't support partial auto-detection, you will need to get software to show you more obscure timings. If you have an XMP profile that you know to be stable, then you may want to use the values from that. I recommend AIDA64, and you can get the trial edition here: Downloads | AIDA64
2. Read the SPD timings for the speed that you want the RAM to run at, and write them down (and note which ones are which).
3. Get into the BIOS, and enable overclocking. Under memory settings, enable <Custom setting>.
Choose the following two options to set the memory speed:
Memory frequency: Setting this to 2000 will set your base clock to the FSB clock, which will be 100MHz by default. Setting it to 2133 will set your base clock to 4/3 of the FSB clock, which will be 133MHz by default.
Memory ratio: Setting this to X will set your memory to base clock x (X+1) (x 2 for DDR).
So for example,
Setting the frequency to 2000 and the ratio to 7 will result in 100MHz x 8 x 2 = 1600MHz.
Setting the frequency to 2000 and the ratio to 9 will result in 100MHz x 10 x 2 = 2000MHz.
Setting the frequency to 2133 and the ratio to 6 will result in 133MHz x 7 x 2 = 1866MHz.
Setting the frequency to 2133 and the ratio to 7 will result in 133MHz x 8 x 2 = 2133MHz.
Setting the frequency to 2133 and the ratio to 8 will result in 133MHz x 9 x 2 = 2400MHz.
4. Copy the SPD timings that you wrote down in Step 2 - in my picture, the timings are more lenient for overclocking. There are three things to note:
tRC: For some strange reason, the BIOS shows two entries under tRC - set the first one to the value from Step 2, and leave the second one at 0.
tCWL (variously called tWCL or tWL): As a rule of thumb, set this to (tCL-1) for low latencies (tCL = 6, 7), (tCL-2) for medium latencies (tCL = 8, 9), and (tCL-3) for high latencies (tCL = 10, 11, 12 etc.) - this is what most boards default to. If you experience instability, you might want to add 1 to this.
tRPab: I have literally never seen this timing before in my life, but apparently setting it to half of RAS seems to do the trick (from both obscure Google results and my tinkering).
5. Do some stability testing. If your settings are unstable, then the machine will either fail to POST, restart, and revert to overclocking off, or (mostly when messing with the CR - <NMode> - setting) be stuck in an infinite boot loop.
If the latter happens, you need to reset the BIOS - follow these instructions from Mr. Fox: http://forum.notebookreview.com/alienware-18-m18x/751794-alienware-18-bios-a07-4.html#post9646431 - after doing this, make sure that the SATA operation mode is the same as before (e.g. AHCI if you had it set to AHCI).
If your settings are borderline stable, then the machine may POST but fail to boot with a paging error - try slower timings or clock speeds. If it boots, run some benchmarks / tests to make sure that there isn't memory corruption.
6. Profit!
Here's my laptop running 4 modules at 2400MHz:
-
-
Sorry that I didn't make it larger
Did you get it to work?
(Guide) How to get the RAM to run at rated (and higher) speeds on AW18 R1
Discussion in 'Alienware 18 and M18x' started by Dodam, Dec 31, 2014.
