Bit more technical if you want,

There are 2 or 3 reasons whay the 3800 is better than the 3500.

First as you have not stated it explicitly and as I can not be bothered to check, the dual core CPU is not marked as 64 bit, now 64 bit, will have larger capacity for floating point numbers and the such and should run faster as a result, can do more with a single operation, however most modern computers are still running 32 bit operating systems, and lets face it why would you be running windows XP 64 on a processor that is not 64 bit (not even sure it would work) so in that respect there is not difference between the 2.

Second, the clock speed, which for AMD's has to be taken with a pinch of salt, the 3500 and 3800 are intel range speeds, so for instance the 3500 will run at the same speed as an intel 3.5GHz processor, for the most part these can be trusted and are useful for comparison. If you want to know more as to why PM and I will explain but I don't think this is the place to get into it. So the higher the number the faster the processor will go the more operations it will do.

Third a dual core CPU is 2 CPU's in one chip, kinda like buy one get one free. So the computer is able to run 2 programs turely concurrently not like single processor where it has to swap all the time. Importantly here if a program has 2 or more threads, which most programs do these days then they will run alot faster. It is likely given the very new nature of the simulators that they are indeed multithreaded.

So in summary

1) no difference
2) 3800 1 3500 0
3) 3800 2 2500 0

result 3800 winner.

HTH

J