Question 5800x3d expected performance with a 2666 cl 16 ram, compared to recommended

[muthgh]

I've a haswel-E built with an msi mb, & a 32 kit of 4x8, dual rank, 2666 cl16 ram sticks, Crucial ballistix Elite BLE8G4D26AFEA.16FAD Crucial - BLE8G4D26AFEA.16FAD 8GB 288pin DIMM DDR4 - Memory Module (compuram.biz) , BLE8G4D26AFEA.16FAD Crucial Gaming Memory (memory4less.com) , a while ago it started having errors "frequent bsods & gpu driver crashes" running with the 4 sticks, then for a while it ran relatively fine with 2 sticks, & now down to 1, msi's x99 MBs had a not so well known issue with ram seating, needing a huge force sometimes, but I'm not so sure it's the same issue this time, I ran memtest86 when it were two sticks & it reported no issues, so I think the 4 sticks are probably fine, & that it's the memory controller that's struggling.
I wanted to build a new pc with 5800x3d "on a budget, a ddr5 platform is too expensive", & was thinking of using those 4 sticks instead of buying a new one if they worked fine, I've two questions:
1-with the Infinity fabric to ram clock relation thing, would I get way worse performance than if I bought a bran new good ddr4 4000 or 3800 kit? the sticks are dual rank too btw according to cpu-z
2-is there any danger to placing those memories not knowing if they have any issues or not? in my current pc they never caused any component to die or anything?
cpu-z screenshots:

 

[CountMike]

I've a haswel-E built with an msi mb, & a 32 kit of 4x8, dual rank, 2666 cl16 ram sticks, Crucial ballistix Elite BLE8G4D26AFEA.16FAD Crucial - BLE8G4D26AFEA.16FAD 8GB 288pin DIMM DDR4 - Memory Module (compuram.biz) , BLE8G4D26AFEA.16FAD Crucial Gaming Memory (memory4less.com) , a while ago it started having errors "frequent bsods & gpu driver crashes" running with the 4 sticks, then for a while it ran relatively fine with 2 sticks, & now down to 1, msi's x99 MBs had a not so well known issue with ram seating, needing a huge force sometimes, but I'm not so sure it's the same issue this time, I ran memtest86 when it were two sticks & it reported no issues, so I think the 4 sticks are probably fine, & that it's the memory controller that's struggling.
I wanted to build a new pc with 5800x3d "on a budget, a ddr5 platform is too expensive", & was thinking of using those 4 sticks instead of buying a new one if they worked fine, I've two questions:
1-with the Infinity fabric to ram clock relation thing, would I get way worse performance than if I bought a bran new good ddr4 4000 or 3800 kit? the sticks are dual rank too btw according to cpu-z
2-is there any danger to placing those memories not knowing if they have any issues or not? in my current pc they never caused any component to die or anything?
cpu-z screenshots:

3600MHz Cl 16 RAM is claimed to be "Best buy" for Ryzen 3000-5000 series on MBs with 400 and 500 cipset, taking "Infinity fabric to ram clock relation thing" above that gains are minimal. On 300 chipset series MBs memory speed and performance are limited no matter which CPU.
Using 4 sticks of RAM still poses some problems to IMC (Internal Memory Controller) and limits it to lower speeds on both,Intel and AMD.
Test your memory at it's base speed to eliminate IMC and MB problems. If they pass tests you should be safe to use them in new system and with 5000 Ryzen and 500 chipset they should run at their XMP at least.
Impact of RAM speed is very limited on Ryzen 5000 and it's performance but programs/games react differently, some do some don't, hard to tell in advance.