Tab left for RAM, right for storage.

https://www.crucial.com/compatible-upgrade-for/alienware/area-51-r2-(late-2014)

This isn't acurate.....It thinks there is two ram slots.

The desktop has 4 ram slots.... though there seams to be some confusion on rather it's a 32 or 64 ram limit.

The hardrive is set up for 64 but there seams to be some software limitations i can't find if they are fixed or not yet.

Also, the Dell service manual lists it as validated to 64GB RAM.

As an aside, the Area 51 R2 was sold stock with a 64 GB ram upgrade option. When it first came out 8GB sticks were the max but 16GB sticks bumped it up to 64GB RAM.  There are no hardware limitations on supporting 64 gb.

"This isn't acurate.....It thinks there is two ram slots." 

The link says there are 4 slots.  2 banks of 2 means two channels, 4 slots.

https://www.crucial.com/compatible-upgrade-for/alienware/area-51-r2-(late-2014)

What about 64gb ram compatablity? Can it do it?

And it don't show what mechanical hard drives are compatable or dose that really matter?

So this should work?

https://www.amazon.com/Mushkin-SILVERLINE-PC4-17000-Dual-Channel-MSL4U213FF16GX2/dp/B07CGNH7JS/ref=sr_1_2?dchild=1&keywords=DDR4-2133+PC4-17000+288-pin&qid=1625527509&refinements=p_n_feature_twenty_browse-bin%3A16158157011%2Cp_n_feature_four_browse-bin%3A10656894011%2Cp_n_feature_five_browse-bin%3A9559990011&rnid=673240011&s=pc&sr=1-2

And can i just buy two and buy two more later.... or do all four slots have to be filled?

I know thats diffrent on some mother boards and stuff and it's changed......  One you could have 1,2,3, or 4 sticks in long as they where all the same..... but another you had to have all 4 filled.

0FRTKJ FRTKJ XJKKD 0XJKKD

https://www.amazon.com/Crucial-DDR4-Desktop-Memory-CT8G4DFRA266/dp/B08C4QF5N4/

Alienware Area 51 R2

X99 MS-7862

Yes that will work fine

2133MHz (PC4-17000)

Low-Voltage 1.2V / Timings: 15-15-15-36

---

@Azraile wrote:

So this should work?

 

https://www.amazon.com/Mushkin-SILVERLINE-PC4-17000-Dual-Channel-MSL4U213FF16GX2/dp/B07CGNH7JS/ref=sr_1_2?dchild=1&keywords=DDR4-2133+PC4-17000+288-pin&qid=1625527509&refinements=p_n_feature_twenty_browse-bin%3A16158157011%2Cp_n_feature_four_browse-bin%3A10656894011%2Cp_n_feature_five_browse-bin%3A9559990011&rnid=673240011&s=pc&sr=1-2

 

And can i just buy two and buy two more later.... or do all four slots have to be filled?

I know thats diffrent on some mother boards and stuff and it's changed......  One you could have 1,2,3, or 4 sticks in long as they where all the same..... but another you had to have all 4 filled.

---

I don't see any issues with the one you selected. 

You should be fine using 1, 2, 3 or 4 slots of RAM.  There's no requirement to use it in dual channel mode. 

However, keep in mind that if you purchase RAM at different times, the sets will be mismatched.  Best practice is to get and use a matched set.  Even buying from the same manufacturer, different (later) revisions may change and result in mismatched RAM that could potentially cause issues.  Most likely you are fine and if timings have changed it'd would just be downclocked to the lowest common denominator but that's always a possibility for issues with mismatched RAM.  

ok I was also thinking about getting a UPS but i know NOTHING about them  like what kinda voltage you need and stuff or if that matters....   like is there a certen voltage i need for the  area 51 R2?