Problem with 1M EURUSD Graph on Oanda

 
When I open 1M EURUSD graph on MT4 it uses more then 500MB of RAM. 2 other 1M graphs use only 80MB. Where can be the problem and how can i fix it or why is this happening? Is it problem on brokers side or platform? Thx
 
Reduce bars on chart to something reasonable like 80K
Reason: