sse asm question

I was playing around with some asm and was wondering. Why is it that when i use sse to manipulate data in parallel that it seems to accumulate errors that i otherwise dont get with my output?

>>3
Umm... also that does not sound like the problem i am having. Let me explain. When doing operation on small sets lets say of 1000 numbers than the errors are small. Only a few decimal places will be off. But if i do operations on large sets like a set of 10000000 numbers than the errors accumulate. The errors also dont present them selfs when I only use the scaler aspects of sse but if i use the parallel aspects then the errors arise.