bdary
Sorry it didn't work out for you.  It was always going to be a 50/50 shot.  Even if you found a kit with the same version #'s, it's still a crap shoot.  When they sell a kit, it's been tested as a kit.  When you try to mix 2 kits, even though it appears to be the same, it was never tested as a "packaged kit".  That makes it a hit or miss thing.
 
When you say you tested with your OC settings, do you mean just the clock speed or do you also mean with the main timings, voltage, etc?  Personally, in this situation I would test all at stock memory settings.  If stable, then load your XMP profile & test before I gave up on it.  As I mentioned above, I ran 2 kits I bought seperatley and they ran fine at XMP, so you just never know until your try it.

Ya, I was told to use these settings in triple channel with my current 3 sticks
 
Memory Frequency - 1600Mhz/2:12
+CL 9
+RCD 9
+RP 9
+RAS 24
+RFC 88
Command Rate 2T
 
Voltage Control 
CPU VTT +100
DIMM Voltage 1.5
 
I guess I could reinstall them and set to default. Then enable the XMP profile. I'd need to probly take a picture of my bio's to show you my settings and if you recommend any changes. Tbh, I'm good at building PCs. But the BIO's is something I only edit if told to by someone way more knownledgeable at it lol.
 
I'll look around then for a full brand new 24GB (6x4G) Kit mebbe I don't have to use corsair but I really like their brand.
 
Any recommendations on cheap but trustworthy brands would be helpful:)

It looks like you've been staying with a Dimm voltage of 1.5v.  If so, that voltage is fine for stock & XMP using the 3 sticks in the kit.  I would bump that up to 1.60v when using the XMP profile or manual and with all 6 sticks.  If that tests stable, then you could back it down a bit to say 1.575v and continue reducing by 25mV increments until you're not stable again.  If you can't make them work at 1.60v, I would up VTT to +120 & test.  If good, reduce slightly. +100 might be just a bit low for what you're trying to do.  A lot of times, the memory controller just isn't up to the challenge either.  You could always try using the timings from the 1600Mhz profile, but lower the clock speed to the next lower speed setting in the BIOS.
 
I was running G.Skill by the way. I've always liked them and they performed well and are usually a bit less in price than Corsair.

I had a couple x58 classy 3 boards and ran 8gb sticks. Get two 16gb kits and just use three of the four. I know other who ran 48gb 6x8gb.
8gb is not on the supported list, but keep in mind they were not on the market when the board was made. They work!
Or just get one 2x8gb and run it in dual mode 16gb and see. I did that too before I got the 2nd kit. 
Doing a lot of math computations and playing games, I can tell you, you will not see a difference between triple or dual mode.
I never ran into an issue running two kids of the same make and model ram in a system. I have seven computers running right now doing primegrid (like prime95) or world community grid running 24/7 with 4x8gb or 4x4 gb with out any issues whatsoever.
Although I went from x58 to x79 to x99 to x299. I will stay here at x299 since it has AVX512 and no E/P core nonsense.
All those systems had more than one kit of ram in it. 
Gskill, Corsair, Patriot are all good brands of memory I am using right now.
 

bdary
It looks like you've been staying with a Dimm voltage of 1.5v.  If so, that voltage is fine for stock & XMP using the 3 sticks in the kit.  I would bump that up to 1.60v when using the XMP profile or manual and with all 6 sticks.  If that tests stable, then you could back it down a bit to say 1.575v and continue reducing by 25mV increments until you're not stable again.  If you can't make them work at 1.60v, I would up VTT to +120 & test.  If good, reduce slightly. +100 might be just a bit low for what you're trying to do.  A lot of times, the memory controller just isn't up to the challenge either.  You could always try using the timings from the 1600Mhz profile, but lower the clock speed to the next lower speed setting in the BIOS.
 
I was running G.Skill by the way. I've always liked them and they performed well and are usually a bit less in price than Corsair.

Thanks so much, Messing with voltages always gvies me sweaty hands lol. I'm super strapped on cash so if something goes wrong, I'm out a PC. I should of saved the $40 I spent on the 3 new sticks and probly just found a cheap G.skill 24GB new kit of 6 sticks. I'll have to find a way to either get these to work or resell them to put towards a that 24GB kit purchase.
 
I'm a noob to OC'ing but, how risky would this be in terms of breaking something. I'm not in a position to replace anything if something goes wrong. I was really hoping these 3 new sticks would just be a plug n' play fix for me. Just asking before I commit to reinstalling these sticks and trying this method.
 
Like give me a scale of 1 - 10 risk lol :)
 
btw heres my bios pic. that I was using I recently set every back down to default but swapped the Mem Freq up from the 1k or w.e to the 1600mhz and left everything else on auto, Now the VTT is still at +100 and the DIMM Voltage Still at 1.5V. Let me know if anything looks out of place. :) I'll give this a shot if the risk is low!
 

bill1024
I had a couple x58 classy 3 boards and ran 8gb sticks. Get two 16gb kits and just use three of the four. I know other who ran 48gb 6x8gb.
8gb is not on the supported list, but keep in mind they were not on the market when the board was made. They work!
Or just get one 2x8gb and run it in dual mode 16gb and see. I did that too before I got the 2nd kit. 
Doing a lot of math computations and playing games, I can tell you, you will not see a difference between triple or dual mode.
I never ran into an issue running two kids of the same make and model ram in a system. I have seven computers running right now doing primegrid (like prime95) or world community grid running 24/7 with 4x8gb or 4x4 gb with out any issues whatsoever.
Although I went from x58 to x79 to x99 to x299. I will stay here at x299 since it has AVX512 and no E/P core nonsense.
All those systems had more than one kit of ram in it. 
Gskill, Corsair, Patriot are all good brands of memory I am using right now.
 

Oh many would it be nice to have the money for 7 computers lol. I'm currently no doing so well on the funds side of things so can't really splurg on new stuff. But it's great to know that I could try to use 8GB Sticks .. See I was totally focused on the 4GB sticks because thats all my Motherboard told me it could handle per dimm slot.
 
Thanks for the band recommendations, Ya I figured those would be the soild choices still. I've been out of the PC building game for a while. This rig is 15 years old shes just finally starting to show her age so I'm trying to keep her togeather with duct tape and bubble gum and I'm all out of bubble gum! lmao
 
:) ty again!

Most of that I got off eBay . Asus Strix x299 for 59$ got an I9-7960x 16 core 32 threads for 125$ and two kits of Gakill Aregis? Mem for 60$. No way I could do it with new hardware.
I have a box in each room and use them to help heat my home. Better than burning oil and I get some scientific research done for BOINC on EVGAs team.
I have found a lot of good deal like that.
I miss EVGAs b-stock used to get my PSUs for good prices. Income tax returns are good time for me to upgrade and sell off my older stuff.
Good luck with your system.

There is always a risk when OC'ing a system, but the little extra voltage increase I mentioned above "should" not cause an issue.  The Dimm & VTT voltages I mentioned were starting points. If you can't get stable at those voltages, I would try to find a single kit. Maybe even like Bill said, go dual channel instead of triple to save a few bucks.  My thinking it that you start at the voltages I said, and assuming stability, you're able to begin to reduce them both a bit for daily use.
 
As far as a risk scale, assuming all the hardware isn't on the verge of dying already, I'd say a 2 or 3.
 
If you feel so nervous & prefer not to have any risk, you could try using just 1 stick from you new kit, add it to the other 3 orginal sticks you had, then put the 4 sticks in dual channel mode and see how it goes with the stock voltages and XMP profile settings.

bdary
There is always a risk when OC'ing a system, but the little extra voltage increase I mentioned above "should" not cause an issue.  The Dimm & VTT voltages I mentioned were starting points. If you can't get stable at those voltages, I would try to find a single kit. Maybe even like Bill said, go dual channel instead of triple to save a few bucks.  My thinking it that you start at the voltages I said, and assuming stability, you're able to begin to reduce them both a bit for daily use.
 
As far as a risk scale, assuming all the hardware isn't on the verge of dying already, I'd say a 2 or 3.
 
If you feel so nervous & prefer not to have any risk, you could try using just 1 stick from you new kit, add it to the other 3 orginal sticks you had, then put the 4 sticks in dual channel mode and see how it goes with the stock voltages and XMP profile settings.

Ahh, okay thanks. I'll give both of these a try. TBH It's not worth my time to refund the 3 I got off ebay for 25$ if they are working I can always resell them to fund a single kit of 24GB later if either of these options don't work for some reason. OCing is something I'd love to try if I could afford to replace anything that goes wrong but atm just not possible. I can't thank you and everyone else for the help here in this matter. I'll keep you updated on things, or if I have any questions that arise during the testing. :) Ty again!

@bdary . Okay. I after setting everything back to defaut in my bios... Pictures Below..

 
 
Volatages set my DIMM auto to 1.700  Still only have the +100 to VTT, The next Option is +125 not 120..
 
 

 
Now my timings are all off
Memory Frequency - 1600Mhz/2:12
+CL 11
+RCD 11
+RP 11
+RAS 29
+RFC 128
Command Rate 2T
 
Just to be clear This is Using all 6 Sticks at once..  
 
This is clearly using a standard profile at 1600mhz, Should I change anything here or wait to see if another bluescreen happens? The 1.70v Is higher than your recommened OC of 1.60v. Anyways let me know what you think just by what you see here so far. I'll keep tabs on crashes and stuff with Bluescreenview. If any happen It took well over 20 hrs for the last crash tho I wasn't doing anything super stressful. lol AHH PC's should just work when told to!
 
 
*(( Update 9hrs and still stable. )) I'll update again later, its bedtime.

You're welcome, happy to help.
I'd say the more relaxed timings are helping for sure.  The 1.70v Dimm voltage is in the green, but I would try to lower it a bit if you can remain stable. Try 1.65v which was pretty standard Dimm Voltage back then.  As far as timings, you may be better off leaving the current timings if having that amount of Ram is more important at this point.  You won't notice much if any difference in performance of normal day to day things, email, internet, gaming, etc.
 
With the VTT, I would leave it at +100 as you try these new Memory timings & voltage.