If you already have 2x512MB or 2x1024MB DDR from the old computer it can be used in the ASRock motherboards. If only a smaller amount of DDR memory is available and buying a whole new PC at once is not possible, it will work until an upgrade can be bought.
Value line DDR2 PC4200 modules from major brands offer excellent price/performance ratios
To upgrade or if there is no spare memory around the cheapest DDR2 533 RAM (also called PC4200) will work good for most. 2x1024MB (2x1 GB) is recommended because it will provide benefits under Windows XP and Windows Vista, you will also notice a difference in multi tasking and some games high end games (Battlefield 2, Oblivion, ?) . Because DDR2 memory is quite cheap at the moment, you will make a good investment by going with 2Gb of system ram. Low Latency timings are not that important for performance
and often slow timings yield very nice frequencies on inexpensive DDR2 533 ram with voltage increases. Therefore it is not required for Overclockers to go with expensive memory and any major brand PC4200 RAM will provide them excellent value unlike the expensive so called ?high performance? sticks that cost a fortune. If you do want to have a bit of overclocking headroom with your memory, then higher rated DDR2 modules (still budget line) from major brands will be excellent. Here?s an overview from prices of 2Gb memory kits at different speeds:Graphics card (GPU):
Positive for the consumer is that the price/performance ratios even for high end cards are still good, so they are good value.
Budget and Silent Buyer who do not want to game are very well off with the integrated graphics card or sticking with their old one in one of the ASRock motherboards.
Best budget VGA card of the moment: NVIDIA 7600GT
For the Gamer a decent midrange gaming solution is the 7600GT and 7600GS, which are available with passive cooling (good for the Silent Buyer). Some X1800XTs in both 256 and 512MB versions get that low in price that they have even a better price/performance ratio despite costing more. For the Overclocker and Silent Buyer, aftermarket cooling is a must on those cards (like the Arctic-Cooling Accelero X2 or Zalman VF900) because the stock cooling is very noisy and does not perform too well.
New high end ATI Card: X1950XTX
For the high end segment, ATI X1900XT can be had for interesting prices and going one step up there is the ATI X1950XTX and the NVIDIA 7950GX2 which is basically 2 cards in one but motherboard compatibility
has to be checked. For the Silent Buyer and Overclocker the lack of decent cooling options on the 7950GX2 might be the deciding factor to go with the X1900XT which can be had with decent stock cooling (like the HIS IceQ) or can be equipped with quiet aftermarket cooling like the X1800XT. The X1950XT already has a good default cooler. (Only with water cooling can the 7950GX2 be kept silent and cool, but it?s very costly).
The often praised NVIDIA 7900GT is a bit stuck in the middle, with ATI?s recent price cuts on the X1900 series the X1900XT has become a better value for money product, offering higher performance for a meagre price bump. The X1900GT is now ~$50 cheaper ($200) and trails the 7900GT only slightly in today?s games.
Because prices for this component vary a lot depending on country, shop and manufacturer it is advised to ask on your local hardware forum what would be best if you are unsure.