XPS 9550 performance decrease suddenly?

Reading the forums on here has helped me solve a lot of problems, but I felt the need to make a post.
After repasting, underclocking by 160mv, cleaning out dust, putting in some thermal pads, changing to ACHI, and installing the XG3 driver for my Toshiba SSD, I had my laptop running great, getting 100 FPS on games where I previously could barely get 35.

Today I updated the BIOS to 1.2.29 and updated the 960M graphics driver. When updating BIOS through SupportAssist I accidently installed a Intel chipset driver that changed the SATA mode back to RAID (found this out because the Intel RST service was running). This changed the XG3 driver back to the Intel Chipset SATA RAID Controller.

Now my laptop's performance is back to where it was before, and I am unsure why (I feel like the drivers are unrelated to the problem, but nothing else has changed).
Max CPU temp around 74C under load and GPU 83C, which is the same as when it was running well, but games are running on lower FPS and feel choppy. Sometimes TDP throttling is reported by ThrottleStop and FPS will drop to 25 in demanding games and 35 in less demanding games (this is with underclock and turbo disabled). I repasted about two weeks ago, so I feel like this should not be happening. I feel like the change back to RAID should not make this much of a difference either.

Is it possible that my repaste job wasn't good enough and after running for a while got messed up or something?

Any ideas on what may have caused this performance drop would be greatly appreciated.

EDIT: I've been trying to fix this for days now to no avail. Things I have tried separately:

Throttlestop undervolt, repaste, thermal pads on chokes/mosfets (using one and also stacking them), cleaning out dust, reverting to old bios and graphics drivers, bump up turbo power max in XTU (the PL1 resets to 45 when idle after decreasing to 7 and causing throttling under load), replacing left VRAM pad that was not touching the heatsink, disable turbo, ultra performance mode in dell power manager, temporarily disable intel DPTF, reinstall IDPTF drivers, speedstep/shift with EPP 0, clean install of GPU drivers.

 

VRM heat?

 

I just read somewhere else that I am supposed to remove the shield on the VRM's before putting the thermal pads on (duh), so this is probably the issue. Will edit this after fixing that pad.

EDIT: Fixing the thermal pad stopped the throttling, but the FPS is still way lower than before. Any other ideas? I'm also unable to see VRM temps in HWInfo and GPU-Z

EDIT 2: Throttling is back :/

 

simple really, step back until it works again
It could be anything you updated so only one way to find out and posting here isn't going to yield the results, only figuring out what update caused it. Start easy, put the old video driver back on, then have a look at the intel driver and if needs be put the old bios back.

(It is worth using DDU to wipe the video drivers out properly)

 

Thanks for the response.
Rolling back the two drivers didn't solve it unfortunately, and I haven't seen any reports on the new BIOS causing performance problems.
The issue (and why I decided to make a post because I can't figure this out) is that the jumps from 30 FPS to 100 did not happen immediately after any of the modifications I made to the laptop (throttlestop, padding, repaste, change to ACHI), it just kind of happened one day, so now that the performance is gone I'm unsure where to go from here

 

Stick the old BIOS back on and test it again

 

Old BIOS didn't fix it, and the throttling is back sadly

EDIT: Found out that AIDA64 can sense VRM temps, gonna see if I can confirm if this is the problem

 

Update:
This is definitely power throttling, as I get throttling no matter what settings I run games on after about 20 minutes (even on ultra settings it plays on low fps but no throttling for a while), and the limit reason in ThrottleStop is PL1. The VRM temp never goes above 70C.
I read about VRAM (didn't know this was different from VRM) temps possibly lowering the power limit, but I have no way of reading the VRAM temperature. If I'm correct, i need to buy more thermal pads to replace the VRAM stock ones?

 

Nothing you can do with pads to stop a PL1 so I really wouldn't bother doing what everyone else tried and removed a day later.

 

What do you recommend to try to fix this? I don't really know how power throttling works. Thanks again

edit: going to look into Dell power manager, IDPTF driver, and resetting bios when I get home, unsure if this is in the right direction

 

Simply put the cpu and gpu have a capped wattage and you are hitting it.

Sent from my SM-G920F using Tapatalk

 

Could something be causing the limits to go down? Before the throttling (lasts about 20 mins) throttlestop will show 15W or higher package power and when throttling it shows around 7W

 

I have not looked into it.

 

So yea, HWInfo says the PL1 is lowered to 7W and this causes the throttling. Unsure why. Side note, when gaming GPU is at 99 or 100% load and CPU usage is low, but temps for both are not that high (Max 65C for CPU and 80C for GPU). Not a VRM issue, I have thermal pads stacked on them to touch the back panel.

 

That is not a fix for the vrm heat issue. Read the threads here carefully and that will give you a better idea of what works and what the limits of the 9550 is.

 

Are you referring to replacing the stock pads on the VRAM? (confused b/c VRAM and VRM are used interchaneably on the threads) If Gonzo understood my responses correctly, he advised me not to do this. Will try it when i get home

 

EDIT: double post sorry

 

Follow GoNz0's advice.

- I was referring to the VRM (voltage regulation module) above and suggesting that stacking thermal pads from the chokes/mosfets to the case bottom generally is not an effective mod.

- With respect to the vram (video ram), don't touch the stock pads unless you have evidence there is a problem with the stock pads. It is difficult to get new pads to fit properly unless you have some experience. More importantly, this is not the root of your problem.

 

I've been trying to fix this for days now to no avail. Things I have tried separately:
Throttlestop undervolt, repaste, thermal pads on chokes/mosfets (using one and also stacking them), cleaning out dust, reverting to old bios and graphics drivers, bump up turbo power max in XTU (the PL1 resets to 45 when idle after decreasing to 7 and causing throttling under load), replacing left VRAM pad that was not touching the heatsink, disable turbo, ultra performance mode in dell power manager, temporarily disable intel DPTF, reinstall IDPTF drivers, speedstep/shift with EPP 0, clean install of GPU drivers.

I have no clue what the problem is anymore. VRM temps don't go above 75C under load, and sometimes throttling will occur when GPU and CPU temps are below 75C. I know I am just trying every suggestion I read, good or bad, but if you think you know the root of my problem I would greatly appreciate it if you could tell me instead of saying what the problem isn't. As far as I know, the only thing I've read on these threads and haven't tried are a cooling pad/fan and internal cooling modifications I wouldn't be confident in doing myself.

 

You can phone it in for a motherboard swap if you feel you have exhausted all options. It has helped in the past but you are playing the silicon lottery. As you have reached the limits of what you are comfortable doing you have no other options. I am sure you have read the hundreds of posts relating to this so I have no idea what you expect anyone else to do.

 

The last thing I might try is making sure you have an older stable BIOS and do a clean install withusing Windows 10/drivers from a few months ago. There is simple ISO and guide in GoNz0's signature. . .

 

Will try this. Thanks