Ram usage shooting up in long missions

[Rhyan_A]

Straight to the point, the ram usage of my warframe.x64.exe is shooting up and using all of my 6gb ram when I am in long missions (20 waves of a def). On a test of doing medium length mission (lets say 10 waves of a def) it still seam to shoot up usage but not as much as a longer mission . I have been trying to fix this problem for 3-4 days now doing everything to my computer other then reformatting it (I literally goggled everything possible). I've got to the point where I don't think its my PC as other games that have higher requirements or equal are working fine.

My consistence of goggling for answers with the problems I am having keeps coming up with similar issues or same issues with "Memory Leak (a failure in a program to release discarded memory, causing impaired performance or failure)" being a possibility, I think this may be the cause however I am no expert, I could be wrong.

This could of been happening for awhile now because since of started a new job time to play warframe has dropped dramatically but over Christmas I have time to run longer missions. This means I can't place a "this happened during this update" tag on it but it is what it is.

Operating System:
    Windows 7 Ultimate 64-bit SP1
CPU:
    Intel Core i7 920 @ 2.67GHz
RAM:
    6.00GB Triple-Channel DDR3 @ 534MHz (7-7-7-20)
Motherboard:
    ASUSTeK Computer INC. P6T (LGA1366)
Graphics:
    1023MB NVIDIA GeForce GTX 560 Ti (NVIDIA)

(yes its a older system now, yes it still works fine, im am saving to get a new one)

I have played warframe for years on this computer without there being any problems on high setting and I have tried lowering the setting to lowest yet the problem still occurs.

Just going to state with didn't know to post this in performance or mission but I went with my gut and posted it here.

Any help, advice or fix for this would be much much appreciated. Thank you