Need Help Solving DPC Spikes Involving Lenovo T430 /w eGPU

[Code_Merk]

Hello, T|I Forum

I looked around on this forum for titles hitting anything similar to this situation, but didn't find anything similar myself.

I am also sorry for this long post, I wanted to be sure to give as much info on the problem as possible to help answer this problem.

Using Nando4's Awesome "DIY eGPU experiences [version 2.0]" guide, I was able to get my setup working very easily with my T420 on Windows 7 Pro. Pleased with how well things were running I decided to buy a used T430 when one passed by my work for refurbishment.<!-- google_ad_section_end -->

At first things were still going well with the setup, I currently have these specs here:

Computer:

• Lenovo T430 /w Intel HD Graphics 4000 (only)
  
• 512 GB SSD (Main Drive) less then 6 months old
  
• 500 GB HDD (Backup Drive) less then a year old
  
• 8 GB of RAM less then 6 months old
  
• Windows 8.1
  

eGPU:

• NVidia GeForce GTX 660 (Would also like to upgrade to the GTX 780 if this issue can be fixed)
  
• PE4H (PCIe passive adapter ver2.4)
  
• Mini to Mini
  
• EC2C
  

The Issues:

After many days (2) of testing and reading through different googled searched forums trying to pin point this issue (not an easy one IMA as the main solution was to "disable each driver one at a time to see it the problem stops" Which ended in a Win 8 Refresh.)

I ended up narrowing it down to the eGPU, as without it the computer runs fine and smooth, can play music and videos without it skipping every few seconds, and even games on low settings (the best this laptop can do without an eGPU :/ ) ran smoothly without jittering all over the place.

However when I attach the eGPU, anytime I open a new window, start watching videos, or play any games, the DPC reading would spike off the charts every few seconds then back to normal. This may seem small, but during this spike, all audio would cut out as well as display a noticeable jitter on anything being displayed real time.

The tool I'm using to read the DPC levels is "DPC Latency Checker V1.3.0" and I was using "LatencyMon" but that would just flood me with more info than I know what to do with.

Other (useful?) Notes:

The system always seemed to do the jittering thing with the T420 as well, but I always pushed that as being just because the GPU was a bit outdated, and the small lag never bothered me as much as it does now on the T430.

The T430 might of had an update to the BIOS too. I now have new options and features I didn't notice before yesterday, something I had to visit yesterday after my SSD refuse to boot and had to reinstall Windows 8.1 when the repair disk would say the SSD was locked, (maybe due to a BIOS setting I changed when telling it to optimize it for Windows 8). As of Now, I have a bear bone Win 8.1 including its updates as well, as well as the latest updates (that I know of) for the chipsets and GPUs.

Also, before the BIOS change, I was never able to run the eGPU on the Express card setting "Automatic" which would allow for Gen 2 devices to connect. Now I can! or so it seems. I now also have no issue turning on the PC with the eGPU already connected and on the "Automatic" setting, where before It would just cause the PC to never boot into windows.

Things I Would Also Like To Know:

This coming PowerBall Numbers?

How to set up my PE4H ver 2.4 to run 2.0 with my 2.0 GPU to my 2.0 Express Card Slot.

• What are the other Channels for?
  
• Why does sticking the mini HDMI cable into PCI x2 instead of PCI x1 not provide power "= to" Gen 2 speeds?
  
• What is the delay switch for?
  
• Why does this board have no instructions when sent to people... This I wounded from day one after receiving the device.
  
• Oh and last (for now) A good thick cable to connect the mini to mini for best data rate... (Does it work like normal HDMI where that can be an issue?)
  

[Code_Merk]

Been doing some more poking around and found this link here:

http://forum.techinferno.com/diy-e-gpu-projects/2102-t430s-egpu.html

Perhaps my T430 is not supplying enough "TOLUD"?

Or perhaps there is not enough bandwidth on the bus to give to my eGPU causing the DPC spikes?

I'm having a hard time understanding this as its not the exact same Laptop, my eGPU is running, and at the moment the numbers have no meaning to me. Any links anyone can provide so that I may brush up on this knowledge?

[Tech Inferno Fan]

PE4H 2.4 can't reliably maintain a gen2 link. Recommend either using a PE4L 2.1 that can or otherwise downgrade the link to Gen1 in the BIOS. This may be the cause of your latency issue.

[Code_Merk]

PE4H 2.4 can't reliably maintain a gen2 link. Recommend either using a PE4L 2.1 that can or otherwise downgrade the link to Gen1 in the BIOS. This may be the cause of your latency issue.

Thank you so much for your reply, I'll still be looking over your guide after this post to try to understand this better, but off the bat I do have some questions for you, and will post back with the answers for anyone else with the same situation if I find them first.

First off, Thanks for telling me about the PE4H 2.4 unreliability with the Gen 2 Link. If there is a better device for the job, I will defiantly get it then. The goal is to get the fastest most reliable setup for this Laptop.

Ok, First Question:

Q: Is this the device you are talking about?

PE4L ( PCIe Adapter ver2.1 )

A: Yes, it is indeed the device, don't let it's size fool you.

Q: If so, How does this tinny thing connect to the GPU? Is another device or adaptor required?

A: No, there is Not another device or adaptor required, it is all that you need. It connects by the front of the GPU between the split on the board.

How it Works:

http://www.hwtools.net/Adapter/PE4L%20V2.1.html

Off Topic Questions:

Any advice on upgrading my Core i5 to i7? Will the extra cores hinder the computer anyway? Will it effect the eGPU at all? How is heat when playing a game?

[Code_Merk]

Update:

Alright I finally purchased a new PE4L today and should be in the mail soon. Will post back when it arrives.

[Code_Merk]

Alright I received the PE4L in the mail and set everything up as so.

BIOS set to Automatic (Gen 2)

Hooked in the connectors (except for the red wire that came with it, Does that need to be connected to the main switch?)

And no more spikes like before. (Yeay!)

Anyway one last question, is the orange light on this thing normal or is there an issue its trying to tell me? (On the PE4L)