My PC is now a bit over one year old and I was thinking about upgrading some parts, but don't know if it's worth it. The current configuration:

Gigabyte GA-P35-DS3 rev. 2.0 board
Intel Core 2 Duo E6550 CPU with 2 x 2.33 GHz and 2 x 2 MB cache
2 GB of DDR2-800 RAM
ATI / AMD Radeon HD 3850 video card with 256 MB

I guess storage and optical units are not that important, but in case they are, I have a Samsung 22x SATA DVD writer and a 500 GB Seagate SATA unit (both devices connected to an AHCI enabled controller). I also have a 1 TB USB disk for documents and other personal files and an additional 1 TB eSATA disk for backups.

Since money is quite limited and I don't want to spend time exchaning the whole motherboard (so Core i7 / Core i5 is not an option), I was thinking about either getting another dual core like the E8400 or a quad core such as the Q9300 or Q9400. The Q9450 or Q9550 that have 12 MB of L2 cache are too expensive unfortunately. If I upgrade, I think I should also get some more RAM but this would mean I'd have to upgrade my Vista OS to 64 bit otherwise I will only see something between 3 and 3.5 GB only (although, if it's 3.5, I wouldn't mind losing 500 MB to be honest).

Your question now probably is what I am doing with the PC at all. Well, except for normal casual stuff like browsing the Internet, writing the one or another Word document or PowerPoint presentation while listening to music, I also do some basic video editing and transcoding (if possible in the future, including HD material) and for my projects also virtualization. For the latter, I recently noticed that RAM is the biggest bottleneck while the CPU can handle two or three Windows 2008 servers running a test installation of Exchange or Office Communications Server quite well.

Video encoding brings us to the next point: does anyone know how fast actually CUDA or AMD Stream enabled encoders are and what the quality is? Encoding a two and a half hours AVC movie recorded over DVB-C or -S takes like one whole day. If quality and speed are well balanced, I might also think about getting a new video card since AMD's Avivo encoder works only for 4xxx series cards and Badaboom only with nVidia GPUs. I don't play much since I have a PS3 for my gaming needs (although I have to admit that I bought GTA IV for PC just to find out that even after installing the newest patches I still have lots of graphics issues which Take 2 claims to come from my low-grade GPU).

So, to sum up, getting a new modern 45 nm dual core CPU would cost me around 150, a quad core with reduced L2 cache would be 200 €. More RAM is 30 € and a new GPU is between 150 € and 200 €, but the GPU is not that important yet. Do you guys think that upgrading the CPU is useful in my case and if yes, would you get a dual core or pay the +50 € and switch to a quad core? According to the Gigabyte website, both the new dual cores and the quad cores are supported by the motherboard with the new BIOS F14 that I installed several weeks ago.

OK, I just ordered a second 2 GB kit that should hopefully be identical to the one I purchased a year ago. I also read an article in c't about mainboards having problems with 4 GB of RAM especially in dual-channel mode when the RAM modules aren't explicitly verified by the manufacturer. I am going to have a dual-boot Vista Home Premium x86 (my current OS) and Vista Business x64 (which I have from my MSDN account) to see if my hardware works fine and then slowly transition to Vista Business and sell my current Viste Home Premium license (should be legal, I hope).

Any idea about my CPU and GPU question?

Installed Vista Business x64 yesterday night and am currently facing trouble getting my video card to work. Vista tells me that the drivers are not digitally signed, but I don't think AMD released the Catalyst 9.3 drivers without signing them - or maybe they did?

Official releases are usually signed or WHQL whatever-ed.

Shouldn't be concerned about it though.

Eventually, it finally worked. I have no idea what was wrong, but I downloaded the installer from another source and manually installed the driver within the device manager.

Now I am running memtest+ with my old 2 GB just to be sure that they are OK and after I get back home I am going to put in the other 2 GB and run memtest+ over night. I also just sold my copy of Windows Vista for 50 € on eBay and am thinking about actually getting a new video card before changing the CPU. I think it makes no sense to upgrade to a dual-core since the difference between my E6550 and the E8400 I wanted to buy for 150 € is not worth it. Better spend the 50 € more and get a quad-core. Does anyone know important the L2 cache is in terms of performance? I am not going to be able to afford the Q9450 or Q9550 that has 12 MB of L2 cache, but only the Q9300 or Q9400 with half the cache (6 MB). With regards to the video card, I was thinking about an ATI HD 4850 that sells for 120 - 150 €. What I don't know is which one to choose in terms of noise. My current Club3D HD 3850 is quite silent and has the original ATI desig so if I get something as loud as my current one, it would be OK.

Damn, when I got back home, memtest+ found 6 errors during a total of 26 passes. The 6 errors were found in 3 specific passes and occurred pair-wise. The first two errors were after pass 16, then 18 and then 26. Wondering how this is possible since the errors were NOT during the tests that involve random patterns.

Anyways, I thought it might be a false positive, put in my two new modules (their sticker is different from the one of the old modules, but the technical specs are identical (DDR2-800, double-sided, 5-5-5-18, same number of memory chips) and started memtest+ to show me several errors starting with the first pass and continuing in the second. Now I swapped the banks, but don't think it will help. When I test the RAM pair-wise (two old ones and two new ones) I don't get any errors within the first 5 passes (although for the old ones, I got some errors during the long-time test as mentioned above).

Weird...

As to the older modules, *might* be heat-related issue.

Blast the modules with compressed air (to remove dust blanket) before testeng.

And while you're at it, blast the motherboard also.

Dust does wonders on computers... the negative kinds of wonders...