List of Simple and Yes or No questions about the Precision T7910 Workstation

Question

1) I bought a T7910 with only 1 Processor, can I add a second Processor later? 
2) Do all 7910 Models come with a dual-processor motherboard?
3) There are videos on Youtube showing a guy changing his 5.25" HDD ports into 2.5" SSD ports with cables, screws, metal plates, and these great little fans and such,  but there seems to be no way to find out where he got the cables, screws and little fans, Do these sort of options, cables, screws, plates and fans etc. come with the T7910?
4) If they do not come with the machine, can they be ordered after the fact? (where? See next question...)
5)  I went to the Dell Parts & Upgrades site then to the 'Accessories for your Dell Precision Workstations T7910' page,.  There was exactly ONE part available for the 7910, (some strange cheap little video card) see here: accessories.us.dell.com/.../Category.aspx;l=en&cs=19&s=dhs&category_id=2999&mfgpid=238987&Tab=Parts&stype=2
so.... 
Is that the ONLY Part or Upgrade one can buy for a Precision 7910 workstation?
(sub question: Where are the Replacement Power supplies and Memory chips and cables and fans and Procs and Drives and Raid Kits for the 7910?
6)  I bought 32GB DDR4-2133 for my 7910 (in a 4x8GB configuration), can I ADD more memory later keeping my existing chips and just adding 4 more 8GB chips to get to 64GB? (or do they all have to be matched chips installed at the same time like the old days...)
THANK YOU!

Answer 1

I just bought my T7910. The short list of specs on mine:
- E5-2623
- 2 x 4GB (2 x 16GB should be coming in this week)
- 310 videocard (already been upgraded to a 960)
- 500GB HDD (already added a 500GB Samsung 850 EVO and a leftover 2TB)
- purchased the quad 2.5" drive bay that goes into the 5.25" optical drive bay to allow me to put in 4 x 2.5" drives besides the standard 4 x 3.5" drives
I bought this system after very detailed research. Not all information and/or parts are straight up available on Dell's site (e.g. the quad drive bay I made sure to be part of the purchase, but knew it would ship separately).
SpeedStep
 1) I bought a T7910 with only 1 Processor, can I add a second Processor later? 
No -> Incorrect: you can add a 2nd processor later, but you'd need to get a genuine Dell heatsink for that 2nd processor, which currently means you'll have to buy that from Dell as I haven't found any resellers offering that heatsink separately yet.
2) Do all 7910 Models come with a dual-processor motherboard?
No -> Yes, all motherboards in the T7910 support dual processors (you just need a 2nd heatsink, which doesn't come with the system if you buy it with a single processor)
3) There are videos on Youtube showing a guy changing his 5.25" HDD ports into 2.5" SSD ports with cables, screws, metal plates, and these great little fans and such,  but there seems to be no way to find out where he got the cables, screws and little fans, Do these sort of options, cables, screws, plates and fans etc. come with the T7910?
No -> Correct, but you can buy them from Dell. The SKU to buy is 470-ABHF. This SKU is probably not findable on dell.com, so you'd have to go through spare parts or your salesrep. Dell's KB article here, shows some information, but at the time I'm writing this it doesn't have a (correct) SKU for the 7910 (it uses different cables than the 7600/7610 due to the 12Gbit/s SAS vs 6Gbit/s SAS).
4) If they do not come with the machine, can they be ordered after the fact? (where? See next question...)
No -> Yes, see above
5)  I went to the Dell Parts & Upgrades site then to the 'Accessories for your Dell Precision Workstations T7910' page,.  There was exactly ONE part available for the 7910, (some strange cheap little video card) see here: accessories.us.dell.com/.../Category.aspx;l=en&cs=19&s=dhs&category_id=2999&mfgpid=238987&Tab=Parts&stype=2
so.... 
Is that the ONLY Part or Upgrade one can buy for a Precision 7910 workstation?
Yes -> No, the website is just very limited in what it lists, even though Dell does seem to have added memory and drive upgrades at least, since your original post.
(sub question: Where are the Replacement Power supplies and Memory chips and cables and fans and Procs and Drives and Raid Kits for the 7910?
No -> You'll have to call Dell spare parts or your Dell salesrep.
6)  I bought 32GB DDR4-2133 for my 7910 (in a 4x8GB configuration), can I ADD more memory later keeping my existing chips and just adding 4 more 8GB chips to get to 64GB? (or do they all have to be matched chips installed at the same time like the old days...)
Yes -> Correct; each processor has 4 memory channels. All usable memory channels have to be identically populated, unless the memory channel isn't being used (e.g. you don't have a 2nd processor to communicate with the 2nd set of 8 DIMMslots, or you don't need that much memory at this time). So, in your case, you would end up with 4 memory channels with 2 x 8GB DIMMs in each memory channel. For my system I should have 4GB + 16GB in 2 of my 4 memory channels for my CPU.