Upgrading RAM

[Oniya]

So, I have an old machine.  It still does mostly all I want, but I'd like to put some more RAM into it.  According to UserBenchmark, I have one slot out of four used, and it holds an unknown 8Gb DIMM DDR3 stick that claims to be 3200 Mhz, but is clocking at 1600 Mhz.  (I frankly believe the latter is a more correct assessment, based on what I know about DDR3.)

My questions:
1) DDR3 RAM sticks are at least 7 years old (released before Q4 of 2015).  You can still get them cheap.  DDR4s aren't too pricey, though.  Can I mix the two, or is it better to stick with one?
2) Needless to say, the motherboard is contemporaneous with the RAM.  Should I even be bothering to think about the DDR4s?
3) Can anyone recommend a reliable site to get RAM?  I had one bookmarked, but I've lost it.

[RedPhoenix]

Your motherboard probably only works with one or the other. If it will take ddr3 you almost certainly can't even put ddr4 ram in there, meaning you literally can't physically attach it.

I always used newegg for computer parts.

[Nowherewoman]

So, I have an old machine.  It still does mostly all I want, but I'd like to put some more RAM into it.  According to UserBenchmark, I have one slot out of four used, and it holds an unknown 8Gb DIMM DDR3 stick that claims to be 3200 Mhz, but is clocking at 1600 Mhz.  (I frankly believe the latter is a more correct assessment, based on what I know about DDR3.)

Sounds like you're running your memory single-channel on a board intended for dual. If you can match the part you've got, or get a new matched pair of 8s (or 16s, depending on your max capacity), you should see an uptick in clock speed. Check your MB manual, if you have it, to make sure of which slots to use and what your RAM ceiling is.

As Red said, even if you can physically put DDR 4 in your current board, it will be locked to the speed of the board, so you won't get any real benefit.

[Oniya]

This was one of those 'box computers', most likely from BestBuy.  So, when it was put together, they only put in the one.  That said, a matched pair of new 8Gs would probably suit me just fine, and still leave an extra pair of open slots if it isn't. 

[Nyxlplyx]

Hey Oniya, if you do the following and find out what kind of motherboard they put into your system, you will be able to look up its specifications online and from there figure out what the max RAM is that it will hold.  You won't be able to upgrade to DDR4 without putting a new motherboard in but you may well be able to find faster and bigger DDR3 sticks if that's all you're looking to upgrade. 

First, open Run using Windows + R. When the Run window opens, type msinfo32 and press Enter. This will open the Windows System Information overview.
Your motherboard information should be specified next to Baseboard Manufacturer, BaseBoard Product, and BaseBoard Version.

If you want any further help looking for minor upgrades, since presumably you don't wish to do a massive overhaul, feel free to PM me.

[Oniya]

Ah, thank you for that - I'll check that out. 

[Nyxlplyx]

Also for your question about where to get it, I always start with Newegg.

[Exaelitus]

Everyone else got the answers.

Just wanted to add:

1) do not mix ddr4 and ddr3. One or the other only.
2) do not do something weird with ram, like 1 stick of 16 gig 1 of 8, 1 of 32, etc. do not do this. Even sticks per slot. For example if you have 2 slots and want 32, then you do 16/16, if you have 4 slots and want 32, then you do 8/8/8/8 etc. you get the idea. This is in the interest of power distribution and when it’s uneven there may be a higher potential for ram failure.

Even if your moba can handle ddr4 I wouldn’t recommend it: a)ddr4 is more expensive, b)what’s the point of going more expensive if you have no intention of getting a new moba. Get the ddr3 that will get the job done and save the money so you upgrade ram, processor, and moba at the same time.