Which is better? High cache memory or low cache?

"Always - More the better.

If you are talking about the CPU cache, Wikipedia says it best -

A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations. As long as most memory accesses are cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory."