Inspiron 660s Upgrade CPU & GPU

your issue sounds like a too weak stock psu to support both i7 and discrete gpu, although gt1030 is a low power card and the system spec supports gt 620 also a low power 30W card, when upgrade from low power i3-3###s to full power i7-3770, there is significant increase of cpu use of system power. possibly motherboard can not supply enough power to discrete gpu, instead using iGPU.  

normally system automatically detects presence of discrete gpu and disables iGPU.  not sure in your case how it does not follow the rule. given the old cpu follows norm but i7 does not, it may be assumed a power issue.

User benchmark reported successful use of i7-3770 and RX580 in 660s. most likely with psu upgrade. https://www.userbenchmark.com/System/Dell-Inspiron-660s/1072

@redxps630Thanks for the reply.  The PSU is my (hopeful) guess too.  I have an Intel i7-3770S on the way and I will try that one next.  It has the same power requirement as the stock i5-3330S:
https://ark.intel.com/content/www/us/en/ark/compare.html?productIds=65510,65702,65701,65719,65524

Alternatively, it's something with the onboard Intel HD 4000 (on i7's) vs Intel HD 2500 (on i3's/i5's).  I also have an Intel i5-3570 and i5-3570S on the way too.  'Cause why save money for a new system when you can spend countless dollars just upgrading the old one!  (Also, I didn't realize before but for most applications the 3570 has as good performance as the 3770 and is only $30 used vs $100 used.)

I did see those benchmarked systems and several users have the 3770/GT 1030 combo, but several more have the 3770S/GT 1030 combo, so maybe that's the better path.

I will update this thread with the details when (not if) I get it working.

I upgraded a 660s from g645 to 3570s a couple weeks ago. I doubt in your case it is the psu that’s causing the problem because it really hasn’t started to consume to much power at start up while it is mostly just idling. In my case it runs on A07 bios but I also don’t have any graphic card. Maybe you should try updating the bios to the latest version. And you are right I picked up the 3570s for only $30 shipped.

@iPadUserThanks for the reply.  I do have the latest (A13) BIOS.  So you haven't tried to run a GPU in your setup?  I have successfully run my stock i3-3330S with a GT 1030 GPU and I have run the i7-3770 with NO GPU.  When the GPU is installed it is not detected by any systems.  My plan is to try an i7-3770s (to see if it is a power issue) and to try an i5-3570 (to see if it is an architecture issue).  My remote backup is to try an i5-3570s as a last resort.

I'll update here with the results.

@ajshafer  - Guess it's always possible the BIOS microcode isn't fully compatible with the i7-3770 so it can't see the add-in GPU.

BTW: Have you tried resetting BIOS with both that i7-3770 and the GPU installed?

1. Power off, unplug
2. Press/hold power button for ~15 sec
3. Open case and remove motherboard battery (check Service Manual for details)
4. Press/hold power button for ~30 sec
5. Reinstall the battery (Time for a fresh CR2032 3-volt coin cell battery? ~$2)
6. Close up and connect mouse, monitor and keyboard
7. Reboot

I hate to crash your thread as I have no good details on the upgrades.  I do have some old links to the subject but found them useless.  I did want to ask, as I am a 660s lover also!  My HDD runs at 47C 24/7, no gaming.  I do sometimes have multiple docs and chrome tabs open and even youtube.  I run light duty stuff on an Intel Core i3 3240, 8GB RAM and an 1TB WD Blue Drive.  The Temps are acceptable but at the upper end of what I would like to see.  Just wanted to confirm that you guys are seeing the same temps?

My ambient temps are around 80F in my room, maybe a little lower.  Certainly we have the A/C on and it feels more like the high 70s most of the time.  House Thermostat is set at 77-78 but my room runs a little hotter.  We can surely start another thread for this as I would like to make a custom duct or fan setup to make it better.  It seems the HDD is sitting in a dead spot, and perhaps I just need one more small fan.  I've been procrastinating because it is a hassle getting to the pc and all the cables.  

Final Summary:

So here's everything that works for my Dell Inspiron 660s (stock PSU, A13 BIOS):
I initially upgraded by adding a Zotac NVIDIA GeForce GT 1030 with my stock Intel i3-3330S, that worked.

I upgraded the CPU to the Intel i7-3770, which worked, but it would NOT detect the GPU (keep reading though).

I changed to the i7-3770S which worked and the GPU worked.

I changed to the i5-3570 which worked and the GPU worked.

So, on a whim, I changed back to the i7-3770 AND IT WORKED WITH THE GPU.  I have no idea how computers work (and I have my BS&MEng in EE/CS from MIT).

I power tested the final configuration (using a Kill-A-Watt at the power plug).  Idle used around 35-45W, full CPU load was 90W, and adding full GPU load was 120W.  I only let the system run for 2 minutes or so but there were no discernible power issues.

User benchmarks here:
i7-3770/GT1030: https://www.userbenchmark.com/UserRun/36947216

i7-3770S/GT1030: https://www.userbenchmark.com/UserRun/36944935

i5-3570/GT1030: https://www.userbenchmark.com/UserRun/36946400

i3-3330S/GT1030: https://www.userbenchmark.com/UserRun/36590235

i3-330S/HD2500: https://www.userbenchmark.com/UserRun/36437784

So, my recommended upgrades for a stock Dell Inspiron 660s are:

CPU: Intel i5-3570 (~$25 used) or Intel i7-3770 (~$100 used)

GPU: Zotac NVIDIA GeForce GT 1030 (~$85 new)

RAM: At least 8 GB of DDR3-1600

HDD: Potentially upgrade from the stock HDD to a SATAIII SSD

Thanks everyone!

@ajshafer  - Glad you got it sorted. Sure was strange...

Wonder if you first install of that i7-3770 didn't make full/complete contact with a CPU pin or with the GPU...?? 

Nothing about HDD Temps?  Anyone experience the same 47C as I do with a standard HDD?  I would imagine with more cpu and gpu temps the HDD would be affected somewhat also.

47c is pretty hot I would think. Don’t think any of the hard drives I have handled previously was any warmer than surrounding temperature. However my 660S has not hdd so I can’t give you a number. It used to have a 500gb western digital from 2012 before I switch it with a Samsung EVO 860 500 gb ssd. But considering your hard drive is almost (I guess)8 years old now maybe you should thinking about switching it out with a ssd. The performance improvement is huge. I used the data migration program provided by Samsung and it was very simple to clone the old hard drive. 

My 660s ( upgraded with i5 3570s, 500gb ssd and 8gb ram) now is running faster than the dell 3880 with 10th gen i3 I picked up on Black Friday 2020. Starting up, shutting down, YouTube and regular web surfing with 660s now is considerably faster than my new computer. it is hilarious.

Both 660s and 3880 costed the same amount originally ($280 in 2012 and 2020 in Black Fridays) 

660s originally had g645 pentiun, 4gb and 500hdd, 3880 has 10100 i3, 4 gb and 1tb hdd. 

@RoHeI have no idea.  How would the CPU work perfectly (full boot, ran benchmarks, etc) but not the GPU if it was misseated?  I did pull and reseat the GPU to see if that was it but no dice (I did not pull and reseat the CPU).  In any event, it works now!  Thanks for the help.

@ajshafer:  Sorry for the Hijack, but it seems relevant to the subject and it seems hard to find others that are so passionate about the 660s.  I love the SFF style as it allows me to run more than one pc in a small space, it's a Dell, and it runs Intel stuff!    

My HDD Temps Thread here

I just wanted to report that I successfully upgrade my 660s with a Xeon E3 1270 v2. Since it's only 69 watt TDP I'm just using the original stock cooler. I saw that it works with some other Dells I have and thought even if it didn't work in this machine it's a safe good buy ($20) though it doesn't have built in graphics so I picked up a basic video card to go with it. Even though it had not been reported on User Benchmarks after checking out that site I decided to just update the BIOS and try and it worked out, I might upload my benchmark info to UB at some point. Great performance for the amount of power.