Memory optimization?

[Forex Trader]

Is there a way to lower or optimize Mt4's memory consumption?
I have 5 insances running on the same server, all are good on memory, except one. All runs the same EA, using around 4,000K, and there is the one using 21,000K.
The charts are down to the minimum. I used to run a very quick strategy on this account though, so the Account history is quite large. Can it cause this memory eating? If so, can it be lowered somehow?

Thank you in advance.