Precision T7810 ram running below what its supposed to

You may consider to test with RDIMM ECC memory.

@Chino de Oro​ how likely is that to be the problem, in your opinion? I can order some but server ram is surprisingly expensive 

Note from the manual pg. 35:  NOTE: If all DIMMs are 2133, the CPU ordered may run the memory at a slower speed.

From the spec sheet:  Quad channelmemory up to 256GB 2400MHz DDR4 RDIMM ECC memory with dual CPUs, 8DIMM Slots (4 DIMMs per CPU). Note: memory speed is dependent on specific Intel Xeon E5-2600 v4 Series processor installed 

I'd attach the manual and spec sheet, but uploads aren't working either, but they can be Googled.

Very likely that would fix the speed issue.  Used server RAM are affordable nowadays.  Processors pricing are dropped to almost nothing.  Specs link is below.

https://www.dell.com/support/manuals/en-us/precision-t7810-workstation/precision_t7810_om_pub/technical-specifications?guid=guid-1a5124e2-8da0-4083-915d-c96dfb9f8d90&lang=en-us

From the spec sheet:  Processor Options: One or two Intel® Xeon® processor E5-2600 v4 Series with up to 22 cores and Intel Advanced Vector Extensions, Intel Trusted Execution Technology, Intel AES New instructions, Optimized Intel Turbo Boost and optional Intel vPro™ technology

For some reason, from the linked website:  4, 6, 8, 10, 12, and 14 core Intel Xeon processor.  Also, it doesn't mention 2400MHz RAM, just 2133MHz.

Precision T7810 Spec Sheet.pdf

Precision T7810 Owner's Manual

@bradthetechnut​ The ram I have is udimm so I think I'll start by getting rdimm and seeing if that increases the mhz. also, I have an e5-2687 v3, but I can get a v4 for pretty cheap ($40ish used). in your opinion, is that a worthy upgrade? 

@Chino de Oro​ I'm going to order 2x8gb of rdimm and see if that fixes the issue, then I'll probably get 2 more sticks. Thanks for your help my man. Also, since this processor's ram compatibility is capped at 2133mhz, would it be worth it to upgrade to an e5-2687 v4? I am looking for better single core performance as this is a budget gaming pc.

If you are planning to upgrade to Broadwell v4 CPU, remember to get your 2400 MHz.  While the E5-2687 v4 will give you getter single core clock, your system may struggle underload with dual 160w CPU.  I suggest to get cheaper dual E5-2680 v4, it has the same multi-core benchmark and slightly lower single turbo clock, but you will have better thermal cooling at 120w TDP.   

@bradthetechnut , the website link was mainly to point out the issue can be resolved if using RDIMM ECC memory type.  The speed will remain the same as 2133 MHz if OP is still using v3 CPU.   

@bradthetechnut​ TEST reply

@Chino de Oro​ I was just going to use one 2687 v4 cpu, it's mainly used as an esports pc and it has a gtx 3050. I just noticed that sometimes this cpu had a slight bottleneck in cpu dependent games. it isn't too bad as it is right now, especially considering I've only put $140 into the build in total, but I would like for it to perform at its capacity

The choice is entirely up to you to decide.  The input was to suggest known working hardware that can provide optimal performance.

After changing to RDIMM memory, let us know if it resolves the memory speed issue.

@roadtrim​ 

Hello

If it's for gaming, why not use 1650 v4  or 1660 v4 ?

Unless you need more core .

@rbxlio​ would they provide better performance in games? i have absolutely no experience with xeons or the lga2011 socket

@Chino de Oro​ i finally got the ram in and its still at 1866mhz. I'm going to get a used cpu off ebay and see if that fixes the problem. unless you have another suggestion? i haven't found anything on this issue at all, which leads me to believe its a problem with my cpu specifically, it performs fine in benchmarks and stress tests, and theres no other reasons for me to believe its my cpu, but im at a loss honestly