[SSDD]

Finally just think about it. You state that you won't "feel" a speed difference yet are doubling the amount of available memory to the PC? Something doesn't add up then.

If the bandwidth of the RAM isn't holding the CPU back then you won't see a difference. If the CPU is processing 5Ghz of data at 100% usage, then 10Ghz and 20Ghz of throughput are going to give you the same result because the CPU is the bottleneck. Also, I don't think the average user is going to notice a 10% bump in speed. Six seconds per minute, although there, isn't a "wow what a difference that made" change.

At the end of the day in regards to the OP's question, I think we can agree that most 2x2 kits are cheaper and won't be slower than a 1x4 kit.

[assassin]

That's the whole point. The end result is a very minimal gain.

[Bleikur]

At last I received all components and as promised I post a photo of the assembled system.

[Case] SilverStone Milo ML03
[PSU] Corsair Builder Series CX430 V2
[Mainboard] ASRock A75 Pro4-M
[CPU] AMD A8-3870K Boxed
[CPU cooler] Scythe Big Shuriken 2 Rev. B
[RAM] GeIL DDR3 EVO CORSA, 4GB (2x2GB), 1.5V, CL9 (9-10-9-28), 1866 MHz (PC3-14900), GOC34GB1866C9DC
[SSD] Corsair Force Series 3 120GB MLC



One thing I stumbled upon is that the heat spreaders of the RAM modules are strictly speaking to high both for the Big Shuriken and the HDD/SSD bracket. As installed in my system the first RAM module is lightly inclined due to lateral pressure applied by the Big Shuriken's heat pipes and the plastic HDD/SSD bracket presses downwards on the second RAM module. Of course this is not ideal but I don't think it will ever be a problem.

One thing turned out to be a problem though. Before doing anything else I was going to update the BIOS to the newest version (have done this on several PCs before without any problems). I followed the instructions of the preferred method provided by ASRock which ended with a message like: "Flashing the BIOS has successfully ended. Please press any key to reboot." Since then nothing appears on the monitor screen when turning on the system. The CPU fan turns but that's it.
I have sent ASRock support a help request and hopefully they will come up with solution soon so that I can start installing Windows and XBMC.

I will report back when the system is up and running but until then I am grateful for any constructive suggestions.

[Bleikur]

I contacted my local ASRock dealer who happens to be agent for ASRock products in Iceland. He offered to examine my motherboard: Cleared the CMOS, replaced the BIOS chip, CPU, PSU and RAM but was not able to boot. He deemed the motherboard broken and will send it to ASRock along with other RMA items.
Unfortunately he does not have a A75 Pro4-M to replace the broken board. He thinks it will take a total of two weeks until I get a replacement which means that I will I be able to assemble my HTPC six weeks after I ordered it. The wait is excruciating.

[GortWillSaveUs]

I contacted my local ASRock dealer who happens to be agent for ASRock products in Iceland. He offered to examine my motherboard: Cleared the CMOS, replaced the BIOS chip, CPU, PSU and RAM but was not able to boot. He deemed the motherboard broken and will send it to ASRock along with other RMA items.
Unfortunately he does not have a A75 Pro4-M to replace the broken board. He thinks it will take a total of two weeks until I get a replacement which means that I will I be able to assemble my HTPC six weeks after I ordered it. The wait is excruciating.

Sorry to hear this news,....
The up-side is that the ASRock dealer was very willing to help.
I've heard horror stories with other manufacturers, so this is great news for all of us who own an ASRock board.
Hang in there,...the time will pass quickly. Just stinks that you received a damaged board.