How Frequently Can Excel Accept Updates?
These are the numbers that we get with an RTD server running on the same computer that Excel is on. Based on a Pentium III 500 MHz processor with 128 MB of RAM, 20,000 unique topics can be updated three times per second; one topic can be updated 200 times per second. The number of times that a single topic can be updated seems to be limited by the number of times that Excel checks for Microsoft Windows® messages, which is at most 700 times per second. Since some of the messages have higher priority than RTD does, Excel effectively gets about 200 updates per second.
