Hi gertjeb,

The 3020 SFF has an Intel H81 chipset which supports the following CPUs:

http://www.cpu-upgrade.com/mb-Intel_(chipsets)/H81.html

The highest rated CPU that Dell shipped with the 3020 was the i7-4790 so the i5-4670K shouldn't be an issue. However, as the 4670K was never validated by Dell I can't say with 100% certainty.

Another consideration is the heatsink, there are two versions, one for CPUs with a TDP of up to 65W and the other for CPUs up to 95W (the 4670K is rated at 84W)

I hope this helps.

https://topics-cdn.dell.com/pdf/optiplex-3020-desktop_owners-manual2_en-us.pdf

The reason I would say no is because the MAX CPU must be 65W or smaller and thats a 84W cpu.

https://ark.intel.com/products/75048/Intel-Core-i5-4670K-Processor-6M-Cache-up-to-3_80-GHz

 If you want a 4670 it MUST BE the 4670S model.

https://ark.intel.com/products/75049/Intel-Core-i5-4670S-Processor-6M-Cache-up-to-3_80-GHz

RX37T i5-4670S,3.10GHz,65w,6MB,FSB 1600MHz,LGA,Haswell

3020 Small Form Factor Default power supply is only 255W

255W L255AS-00 PS-3261-2DF Power Supply
Optiplex 3020 7020 9020 Precision T1700

Small Form Factor (SFF)
Part Number: YH9D7 R7PPW NT1XP 3XRJ0 V9MVK FP16X T4GWM M9GW7 FN3MN

3020 Small Mini Tower  Default power supply is 290W

The 4790 that works is the 4790S which is a 65W CPU.

https://ark.intel.com/products/80808/Intel-Core-i7-4790S-Processor-8M-Cache-up-to-4_00-GHz

XRY60 i7-4790S,3.20GHz,65w,8MB,FSB 1600MHz,LGA,Haswell
2VC8F i7-4770S,3.10GHz,65w,8MB,FSB 1600MHz,LGA,Haswell

H151Y i5-54460S,2.90GHz,65w,?MB,FSB 1600MHz,LGA,Haswell
RX37T i5-4670S,3.10GHz,65w,6MB,FSB 1600MHz,LGA,Haswell
0HP1C i5-4570S,2.90GHz,65w,6MB,FSB 1600MHz,LGA,Haswell
P22T4 i5-4440S,2.80GHz,65w,?MB,FSB 1600MHz,LGA,Haswell

PX8R2 i3-4170,3.70GHz,54w,3MB,FSB 1600MHz,LGA,Haswell
KYD5C i3-4170,3.70GHz,54w,3MB,FSB 1600MHz,LGA,Haswell
05MXD i3-4160,3.60GHz,65w,3MB,FSB 1600MHz,LGA,Haswell
P5FJT i3-4130,3.40GHz,65w,10MB,FSB 1600MHz,LGA,Haswell
M18KC i3-4160,3.60GHz,65w,3MB,FSB 1600MHz,LGA,Haswell
CX4JJ i3-4150,3.50GHz,65w,3MB,FSB 1600MHz,LGA,Haswell
J0VNG i3-4150,3.50GHz,65w,3MB,FSB 1600MHz,LGA,Haswell

HKMFY G3260,3.3GHz,54w,3MB,LGA,Haswell
FFYG3 G3250,3.20GHz,65w,3MB,FSB 1600MHz,LGA,Haswell
37RPN G3250,3.20GHz,65w,3MB,FSB 1600MHz,LGA,Haswell
9H4P2 G3240,3.10GHz,65w,3MB,FSB 1600MHz,LGA,Haswell
5RY21 G3220,3.10GHz,65w,?MB,FSB 1600MHz,LGA,Haswell
HRFH7 G1840,2.80GHz,65w,?MB,FSB 1600MHz,LGA,Haswell
HKGVH G1820,2.70GHz,65w,MB,FSB 1600MHz,LGA,Haswell

 I found this....

The Dell Optiplex 3020 MT will take a Intel i5 4570 84 watt processor.

Likely any Intel i7 processor socket LGA1150 that is 84 watts should not be an issue for the 3020 MT platform.

If you dont mind me asking, where'd you find this?

Optiplex 3020 Spec. Sheet  

Screengrab below is from a borrowed post.  Image sbows once approved by a moderator: 

https://ark.intel.com/content/www/us/en/ark/products/80814/intel-core-i7-4785t-processor-8m-cache-up-to-3-20-ghz.html

https://ark.intel.com/content/www/us/en/ark/products/77488/intel-core-i3-4160-processor-3m-cache-3-60-ghz.html

Hi!

I tried to change the CPU in my 3020 SFF from i3 4160 to i7 4785T but I only get the amber 2,3 error code.

Do you have any clue, why this cpu might be not supported?

Thanks! 

BR,

Jeno

Hi Gert,

I didn't know that a lower TDP can be a problem. So if I choose an other i7 with higher TDP, it'll work?

BR,

Jeno

Jeno,

it wil not work.

The i3 has a TDP for 54 W and the i7 is 35 W

All the processors wich end with a T at the end are 35 watt

Gr.

Gert