16gb RAM installed, why's it say only 15.4gb usable?

Windows dedicates ram as virtual memory that's located under control panel system.

That amount automatically will change its a cache on the ram and it's vital to have! Don't mess with it! 500 MBs of cache is small it should have 4 gig in manual setting for maximum quickness .

But windows discards all but the most important files in the cache or page file again leave it alone nobody uses 16 gig of ram! That's 2 whole DVDs worth of information !

Your operating system is only 5 gig! If you want real speed you need to get a SSD instead of a physical hard drive!

You have all that good ram but it can't move any faster than that slow hard drive 8500 rpm if your lucky!

Get a SSD which runs 235000 rpm equivalent.

Then watch stuff load in the blink of an eye!

Yes, it's deducting that 600mb of memory to reserve it for the integrated graphics.

If you add a dedicated graphics card to your computer then you will have full use of your RAM. However, for today's computing needs 16gb is more than enough unless you're running a highly CPU intensive Video Editing program. And if you were video editing, you would greatly benefit from a dedicated video card.

I have 16gb of RAM in one of my PC's and all 16gb are usable because I have a dedicated card in that PC.

That 0.6 GB of RAM isn't going to give your computer any more 'potential'. More RAM doesn't increase a computer's speed, it just gives it more room to work if you need it. Just watch your usage in Task Manager, normal tasks usually don't need more than 4 GB.

If you're actually close to using that much RAM you need to upgrade.

But yes, these other guys are right, some of your RAM gets used for system tasks that you can't use, such as video memory. Some of it will be the way they advertise memory capacities, though that affects hard drives more than RAM.

If you have a dedicated video card in your system it may help to disable your integrated graphics chip, that might reduce how much of the RAM is reserved for video.

- Try going into the BIOS & see what BIOS tells you. Is it 15.4GB RAM or 16GB RAM?

- Open your computer & try switching your memory sticks into different slots

- What does your Windows Task Manager report for Total RAM?

If you can't manage to solve this issue, then 15.4 GB is usable space & rest occupied by system reserves

Part of the RAM is allocated for integrated graphics and unavailable for the OS to use. Many manufacturers don't allow you to adjust this manually. If you can it would be in the BIOS settings when the computer first boots.

The missing ram is used for the dedicated, on-board video card. It's what give you the image on the screen.

cos some is used by the cpu/gpu.or you have shadowed some of it. or you have set the CPU.gpu to be the FIRST(the default...the windows one) instead of you add in pci-e card. it would be most unlikely to have ALL 16gb available to an OS.

Any OS would requiring some reserves like that.

Its the way you calculate what 16GB is. 1k is not 1,000 but 1024....

broke