Today's 486 and Pentium processors are so fast that they often wait for data from system memory. Installing an L2 Cache Memory Upgrade can keep information flowing to your systems data-hungry processor and boost overall system performance. ??This is a 256KB cache memory module designed by Kingston technologies for IBM Aptiva 2144 131/133, 141 etc; and for Aptiva 2168 132/142, 152/154, 931/93W/932/934/935 and so on.