Anyone considering adding extra memory to a personal computer to facilitate the upgrade to Windows XP will be wishing they'd done so earlier. Memory prices have been rising steadily since November and have registered large jumps in the first few trading days of this year — jumps that are quickly being reflected in retail prices.

"Prices have been going up ever since before Christmas," said Clive Ong, an analyst at memory market watchers ICIS-LOR in Singapore. Ong said a combination of factors are behind the rise, which has become steeper since the beginning of 2002.

Consider a 256MB stick of SDRAM (synchronous dynamic RAM), the most common type of PC memory. At the beginning of November these were changing hands for around £13 on Asia's memory spot market, according to ICIS-LOR. This had almost doubled to £21 by the end of 2001 and now sits around £37 — a near tripling in price over two months.

The price of faster and higher specification DDR (double data rate) SDRAM has also registered similar gains, said ICIS-LOR.

One of the factors driving up prices is an anticipated merger or joint venture between Micron Technology, the second-largest manufacturer of DRAM chips, and South Korea's Hynix Semiconductor, which is also a major manufacturer.

The analyst also cited market acceptance of earlier price rises by manufacturers.

Not all memory prices are rising however. Rambus RAM, a proprietary memory used mainly with Intel's Pentium 4 chips, is falling.

The price gap between Rambus DRAM and DDR memory now down to around £3.50 on the spot market — a far cry from the £41.50 difference at the beginning of November.

But this isn't the great news for Rambus it appears. "Many manufacturers are producing DDR and it is easier to make than Rambus [DRAM]. The production technology is very close to SDRAM and you don't need to completely overhaul your plant to produce it," said Ong.