The RAIDION hardware based controller LTX (Gandiva), LTX+ (RAIDIONplus), LTXes (RAIDION.es) can accommodate one pair of standard 72 pins SIMM as its Cache Memory. Both pair must be of the same size SIMM. This provides from 8MB to 128MB of total Cache Memory. http://www.raidionsystems.com/html/cache_memory.htm Benefit of a larger Cache Memory size: Our lab testing shows that the most ideal Cache Memory is 32MB. Larger Cache Memory size does not improve performance any further. Identify Cache Memory size: Using the serial port or the Lookout Utilities (LTX+ and LTXes only), navigate to System Information section via Statistics > System Information. Sorry, can't get this info using just the LCD/Keypad. On the early days of this product, all systems were shipped with 8MB of total Cache Memory size. Current systems are shipped with larger sizes. Battery Backup: Some LTX+ and LTXes factory equipped with 8MB total Cache Memory uses battery backup SIMMs (two 4MB). These are custom designed SIMMs to give on SIMM battery backup. These SIMMs can be expanded to 8MB each by adding snap on chips to the SIMMs, giving a total of 16MB battery backed up Cache Memory. If you desire to go beyond this size, you will have to use `normalī SIMMs and give up the battery backup feature. If you want to increase your 8MB total Cache Memory, we encourage you to use `normalī SIMMs approach instead of the snap on chips. The snap on chips are becoming less available and are very costly. Yes, you will be giving up the battery backup feature, but if the controller is on an UPS your are covered, or if your entire system (server included) is not on an UPS, then just having the RAID SIMMs battery backed up will not provide any benefit. The older LTX (Gandiva) does not have and can not use the battery backup SIMMs. Specifications of SIMM: 72 pins, 60ns, 4MB, 8MB, 16MB, 32MB or 64MB. Parity for LTX (Gandiva) Parity or No Parity for LTX+ (RAIDIONplus) Parity or No Parity for LTXes (RAIDION.es) Access to the SIMM sockets: The controller module must be removed from its plastic housing for desk top towers or its rack mounted position for rack mounted controllers. On the RAIDION.plus and RAIDION.es , there is an access panel at the top of the controller module, remove this panel to access the SIMM. On the Gandiva, the entire top cover must be removed to access the SIMM. You will have to cut the warranty seal to open the cover. Do this at your own risk. RAID configuration info: The RAID configuation information are stored on the disk modules, no configuration information are stored on the SIMMs. So donīt worry about loosing your RAID configuration when chaning the SIMMs. But as always, you should backup your data before attempting any changes to the RAID.