Question Cinebench R15 CPU score decreased after changing GPU (Ryzen 3 1200)

[Exploding PSU]

Greetings,
So, this might not much of an issue, but I'm still rather worried (or puzzled should I say)... Specs are (or were) :

• Ryzen 3 1200 (stock cooler)
• GeForce GTX 970
• ASRock A320M mobo
• Apacer 8 GB DDR4 memory (2400, single channel)
• 500 GB 5400 RPM HDD
• 500 W FSP PSU

Everything is stock, just like how they came out of the factory. No overclock or whatever. As is.
The PC with this configuration scored 467 cb on the CPU test with Cinebench R15, which is fine (pretty much every review I read put it on 450+ range, so pretty much spot on)

Then, my GTX 970 died several weeks ago, and I replaced it with a Vega 56 (ridiculous bottleneck, I know, but it was a long story with the Vega), and I replaced the PSU to go with the Vega (now a Seasonic 650W). Anyway, after I installed the GPU and finished setting it up (reinstalled driver, etc), I fired up Cinebench R15, ran the CPU test multiple times, and to my surprise, the system only scored 350-ish on the CPU test (lowest being 314). I ran it several times and got similar results (350-357 range). I'm surprised as to, why? The CPU's temp maxed out at 57 C so I guess it's not a cooling / throttling problem. Why would replacing the GPU (and the PSU) have any effect on CPU score? And why did it score lower than before, with everything else being equal? I didn't touch anything else besides uninstalling NVIDIA GPU drivers and installing the AMD drivers, nothing else have changed. So, what gives? Did I miss something??

I know this doesn't mean much but I'm afraid the lower scores indicate something's wrong with my CPU, and it might bottleneck my already-bottlenecked system even more.
Thank you in advance..

 

[Lutfij]

Did you use DDU to rid the system of your Nvidia drivers? Are you on the latest BIOS update for your motherboard? Check back with the version of the drivers you're using for the AMD card since Windows 10(I'm assuming) will download drivers on it's own. Speaking of 10, which version of the OS are you currently on?

 

[Exploding PSU]

Did you use DDU to rid the system of your Nvidia drivers? Are you on the latest BIOS update for your motherboard? Check back with the version of the drivers you're using for the AMD card since Windows 10(I'm assuming) will download drivers on it's own. Speaking of 10, which version of the OS are you currently on?

Wow, that was a quick one..
Yes, I used DDU to uninstall the Nvidia drivers. Not sure about the BIOS version, I'll check it later (I'm using the PC to type this, so I'll have to restart, right?). I downloaded and manually installed the AMD driver from their site (the Radeon Settings reported 19.5.2). The OS (as reported by winver) is Windows 10 (version 1809, OS Build 17763.557)

EDIT : I just checked, the latest BIOS is version 2.10 which was released just 3 days ago. Should I update it first?? (the one I have is version 1.0.0.0a)

 

[mdd1963]

You are running half of normal RAM bandwidth, an odd intentional handicapping choice if/when also utilizing $300-$400 GPUs...

 

[xravenxdota]

Just double check your memory speed in bios may have declocked herself can never be to sure(my old pc had this habit of declocking :O)Another thing is update your windows 1809 is horrible.I had to install win 10 1803 and updated 1903 which was a mission as 1809 and 1903 fdidn't see my raid setup even after pointing it to driver and then i had to dl 2 additional chipset made by amd just to update to 1903.Fk man i so hate microsoft's anti amd bs 😀.Reason why i mention that is cause you will also have to install the amd drtivers when you update to 1903 but windows update will point it out to where to go.

 

[Exploding PSU]

You are running half of normal RAM bandwidth, an odd intentional handicapping choice if/when also utilizing $300-$400 GPUs...

Yeah, I know.. I wasn't thinking straight when I bought the RAM. Should've chosen the 4x2 instead. New RAM is now on my upgrade list..

Just double check your memory speed in bios may have declocked herself can never be to sure(my old pc had this habit of declocking :O)Another thing is update your windows 1809 is horrible.I had to install win 10 1803 and updated 1903 which was a mission as 1809 and 1903 fdidn't see my raid setup even after pointing it to driver and then i had to dl 2 additional chipset made by amd just to update to 1903.Fk man i so hate microsoft's anti amd bs 😀.Reason why i mention that is cause you will also have to install the amd drtivers when you update to 1903 but windows update will point it out to where to go.

I've checked the speed, and nothing is wrong. About the windows update, there's nothing much I can do. I can't afford to reinstall windows (I'm on metered connection), guess all I can do is wait for Microsoft to fix their OS (again)..

Just tried running Cinebench on Safe Mode, and guess what, I got 482 score, the highest I've ever scored. But running Cinebench on 'normal' mode and score dropped to 350-ish yet again.. I guess something is bogging down the system, causing the drop. At least it's good to know it's not a hardware problem...