Listen
Hypermemory is a technology which shares memory from RAM and uses it for its own use, just like onboard cards. This is done to make them economical by giving less memory to itself.
Now, Obviously one will think that ONE will get a PERFORMANCE HIT. Quite true. But sometimes on chipsets like that X300 itself, more memory is helpful in getting better frame rates. THIS ONLY APPLIES TO LOW END CHIPSETS. Incase its an external card , i wouldnt recomment Hypermemory, simply because of the performance hit. Though if you are on a budget, you can opt for one only if you have high RAM. I recommend 1 GB +
Also , i think X1400 normal would be much better ( External )