Asus EeeBox EB1021 screen corruption after RAM upgrade

[Phylyp]

I have an Asus EeeBox EB1021, that shipped with 1 x 2 GB RAM (Hynix, 1333 MHz DDR 3). I have been trying to upgrade this to 4 GB, and have always failed.

This model has two slots for DDR 3 laptop RAM. The bus speed is 533 MHz (since it uses the AMD E-350 APU), so faster memory is slowed down. The OS is Win 7 HP x64. It drives a 1920x1200 monitor over HDMI. A 4 GB SDHC card is dedicated to ReayBoost.


I have tried these combinations:

1. 2 x 2 GB (the original Hynix stick and a 2 GB Kingston stick)
2. 1 x 4 GB Kingston 1333 MHz stick
3. 1 x 4 GB Corsair 1333 MHz stick
4. 1 x 2 GB (the 2 GB Kingston stick)

All these combinations cause the following problem:

1. The memory is recognized in the BIOS (AMI UEFI) and by Windows. Computer boots up fine.
2. Certain operations cause distortion lines to appear on the screen (similar to what happens when a video card is faulty). These operations are: running Windows Experience Index, or opening CPU-Z (the SPD detection part of CPU-Z startup appears to be what triggers it). Once the lines appear, they don't disappear until a reboot.

Here is my analysis/understanding (feel free to correct me if wrong):

1. Its not faulty RAM, because the same Kingston & Corsair sticks work in another machine without any issues at all.
2. Its not dirty/faulty RAM slots in the EeeBox, since the original 2 GB Hynix stick by itself is perfectly happy in either of the two slots.
3. I've got clean power to the PCs, it runs through an APC UPS.
4. I've tried changing the memory speed in BIOS from the default 533 MHz down to 400 MHz, which delays the problem occurring, but doesn't resolve it.
5. The BIOS has an option for 'memory bank interleaving'. Enabling it or disabling it has no effect.
6. I've flashed the latest BIOS (version 0402) for my model, prior to attempting all upgrades.
7. Having looked at the Asus forums, I notice that other models of the Eee PC and EeeBox have had similar issues, where it is very finicky about the RAM used.
8. Swapping back to the original Hynix stick always resolves the issue.

• Any guidance on what might be causing this issue?
• Any suggestions on what RAM sticks to try? Will it be worth trying out 1066 MHz sticks, so they're compatible with the 533 MHz memory speed?

 

[Zap]

You can run CPU-Z to see what memory timings the motherboard is trying to run, and then find out if the RAM's SPD supports those timings/speeds. Note that there is no performance difference between a single stick and two sticks because the memory controller is single channel only.

BITD my MSI Wind needed some really high end RAM to be able to overclock, because latency was locked pretty low. Maybe your EeeBox is similar in that it needs something particular.

 

[BrandonT]

I know with my 1001P I had to turn off "quick boot" in the BIOS so it would properly read the ram timings.

 

[Phylyp]

@Zap: CPU-Z reports that it is running with timings of 7-7-7-20 (533 MHz). All of the RAM sticks I tried support this (according to their SPD tables in CPU-Z, though their default is 9-9-9-24 (667 MHz).

I'm not overclocking here, but I take your point about my EeeBox being fussy

@BrandonT: That's an interesting point. However, my EeeBox (model EB1021) doesn't have a quick boot option (probably since it uses UEFI). I've also made sure I always entered the BIOS screen to verify the memory modules there, before rebooting into the OS - like you, I've found that this ensures that the firmware/OS are able to see the newly added RAM.

Thank you both for your input.

I have taken the plunge, and bought a 1 x 2 GB stick with defaults at 533 MHz (7-7-7-20); same as what the chipset enforces.
So right now, I've got:
1 x 2 GB (667 MHz stick running at 533 MHz - this is what was always stable)
1 x 2 GB (533 MHz stick running at 533 MHz - the new stick)

Its been running this far without any issues, let me keep an eye on it.

 

[Phylyp]

So, I've been running the below two sticks:
1 x 2 GB (667 MHz stick running at 533 MHz)
1 x 2 GB (533 MHz stick running at 533 MHz)
They're running at 7-7-7-20, per CPU-Z.

I've not seen any problems thus far. I'm cautiously optimistic that the problem is resolved, though for the life of me I don't understand why the OEM 667 MHz stick works, and retail ones didn't!

Thank you all for your inputs, much appreciated.