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I recently upgraded my RAM from 4x1GB Corsair XMS2 to 4x2GB Kingston Hyper-x because I found that I was maxing out when running FDT, Firefox 5 and Photoshop together for any length of time.

At the time that I realised how high my RAM usage was I also noticed that I was getting large amounts of hard faults while the applications were open but idle, often showing more than 100/sec for 15-20 seconds at a time. I imagined that these would clean up with new RAM, but I still see large amounts as the OS and various associated applications start up, and sometimes when FDT in particular is performing an operation.

Is this likely to just be caused by required parts of applications not being found because they're still starting up, or should I worry about the quality of the new RAM that I have bought?

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up vote 9 down vote accepted

Hard faults, also known as page faults, are normal and not caused by faulty memory.

See for more details.

Basically a high fault per second rate would indicate that a program is continually have to (get the operating system to) swap bits in and out to hard-disk and since that is slow, adding extra memory may help overall performance.

But as you have mentioned, applications starting up can cause a temporary blip.

But, I don't think a fault rate of 100/sec is particular high.

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It's certainly way above 100/sec. I put that because that's what the graph tops at, but it's more like 400-500/sec at times. Still if it's not representing an actual hardware fault then I'm happy, with the extra 4GB I'm definitely feeling a performance boost. – shanethehat Jul 23 '11 at 18:05
So, if it runs out of RAM it starts using the HDD to cope causing staggers/lag? I have the same problem with BF3 as described here. And the game will go into lag mode (caused by PC) for up to 30 seconds. And once it happens tends to reoccur often. Have 4GB (2x2GB). Recommend adding another 4GB? – Doomsknight Mar 5 '12 at 10:17
If you are running low in memory then adding more memory will help providing your system supports it. 32-bit windows will not support more than 4Gb, so you need 64-bit windows. You also need to check that your machine (ie motherboard/bios) supports it. If you need to change to 64-bit windows, you need to make sure that any essential applications/games will run with 64-bit windows (unless you want to run them in a Virtual XP mode.) If you are running low on memory when just running just particular application, you need to determine if that application will take advantage of the extra memory. – sgmoore Mar 5 '12 at 19:50

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