Lowest power CPU for a Vostro 470 desktop; Xeon E3-1220L?

Hello!  The Processors you specified are socket LGA1150 and will not fit in your motherboard with an LGA1155.  You can set up in Windows a lower power management via the control panel so the processor uses less energy.  

@BMT1979, thank you.

So to ask my question more correctly, what other CPUs are compatible?  This seems to be the official list:

* Intel Core i7-3770 (K), 2700, 2600 (K)

* i5-3570 (K), 3470, 3350P, 2500 (K), 2400

But Intel's site shows the H77 chipset compatible with many other CPUs:

Intel® Core™ i7-3770T Processor Launched 4
Intel® Core™ i7-3770S Processor End of Life 4
Intel® Core™ i7-3770K Processor End of Life 4
Intel® Core™ i7-3770 Processor End of Life 4
Intel® Core™ i5-3570S Processor End of Life 4
Intel® Core™ i5-3570T Processor Launched 4
Intel® Core™ i5-3570K Processor End of Life 4
Intel® Core™ i5-3570 Processor End of Life 4
Intel® Core™ i5-3550S Processor Launched 4
Intel® Core™ i5-3550 Processor End of Life 4
Intel® Core™ i5-3475S Processor End of Life 4
Intel® Core™ i5-3470T Processor Launched 2
Intel® Core™ i5-3470S Processor Launched 4
Intel® Core™ i5-3470 Processor Launched 4
Intel® Core™ i5-3450S Processor End of Life 4
Intel® Core™ i5-3450 Processor End of Life 4
Intel® Core™ i5-3350P Processor End of Life 4
Intel® Core™ i5-3340S Processor End of Life 4
Intel® Core™ i5-3340 Processor End of Life 4
Intel® Core™ i5-3330S Processor End of Life 4
Intel® Core™ i5-3330 Processor Launched 4
Intel® Core™ i3-3250T Processor Launched 2
Intel® Core™ i3-3250 Processor Launched 2
Intel® Core™ i3-3245 Processor End of Life 2
Intel® Core™ i3-3240T Processor Launched 2
Intel® Core™ i3-3240 Processor Launched 2
Intel® Core™ i3-3225 Processor End of Life 2
Intel® Core™ i3-3220T Processor Launched 2
Intel® Core™ i3-3220 Processor Launched 2
Intel® Core™ i3-3210 Processor End of Life 2
Intel® Core™ i7-2600S Processor End of Life 4
Intel® Core™ i7-2600K Processor End of Life 4
Intel® Core™ i7-2600 Processor Launched 4
Intel® Core™ i5-2550K Processor End of Life 4
Intel® Core™ i5-2500T Processor End of Life 4
Intel® Core™ i5-2500S Processor End of Life 4
Intel® Core™ i5-2500K Processor End of Life 4
Intel® Core™ i5-2500 Processor End of Life 4
Intel® Core™ i5-2450P Processor End of Life 4
Intel® Core™ i5-2405S Processor End of Life 4
Intel® Core™ i5-2400S Processor End of Life 4
Intel® Core™ i5-2400 Processor Launched 4
Intel® Core™ i5-2390T Processor End of Life 2
Intel® Core™ i5-2380P Processor End of Life 4
Intel® Core™ i5-2320 Processor End of Life 4
Intel® Core™ i5-2310 Processor End of Life 4
Intel® Core™ i5-2300 Processor End of Life 4
Intel® Core™ i3-2130 Processor End of Life 2
Intel® Core™ i3-2125 Processor End of Life 2
Intel® Core™ i3-2120T Processor End of Life 2
Intel® Core™ i3-2120 Processor Launched 2
Intel® Core™ i3-2105 Processor End of Life 2
Intel® Core™ i3-2102 Processor End of Life 2
Intel® Core™ i3-2100T Processor End of Life 2
Intel® Core™ i3-2100 Processor End of Life 2
Intel® Pentium® Processor G2140 End of Life 2
Intel® Pentium® Processor G2130 Launched 2
Intel® Pentium® Processor G2120T End of Life 2
Intel® Pentium® Processor G2120 Launched 2
Intel® Pentium® Processor G2100T End of Life 2
Intel® Pentium® Processor G2030T Launched 2
Intel® Pentium® Processor G2030 Launched 2
Intel® Pentium® Processor G2020T Launched 2
Intel® Pentium® Processor G2020 End of Life 2
Intel® Pentium® Processor G2010 End of Life 2
Intel® Pentium® Processor G870 End of Life 2
Intel® Pentium® Processor G860T End of Life 2
Intel® Pentium® Processor G860 End of Life 2
Intel® Pentium® Processor G850 Launched 2
Intel® Pentium® Processor G622 End of Life 2
Intel® Pentium® Processor G840 End of Life 2
Intel® Pentium® Processor G620T End of Life 2
Intel® Pentium® Processor G620 End of Life 2
Intel® Celeron® Processor G1630 End of Life 2
Intel® Celeron® Processor G1620T Launched 2
Intel® Celeron® Processor G1620 Launched 2
Intel® Celeron® Processor G1610T Launched 2
Intel® Celeron® Processor G1610 Launched 2
Intel® Celeron® Processor G470 Launched 1
Intel® Celeron® Processor G465 End of Life 1
Intel® Celeron® Processor G555 End of Life 2
Intel® Celeron® Processor G440 End of Life 1
Intel® Celeron® Processor G550T End of Life 2
Intel® Celeron® Processor G550 End of Life 2
Intel® Celeron® Processor G540T End of Life 2
Intel® Celeron® Processor G540 Launched 2
Intel® Celeron® Processor G530T End of Life 2
Intel® Celeron® Processor G530 End of Life

This entire list may not be supported by the 0YJPT1 mainboard, but some might.

Here is my pick of the 'low TDP' processors in that list:

Celeron G540T
Pentium G620T
i3-3250T
i5-3470T
i7-3770T

All will generate less heat, fan noise and use up to half the power, but none of these are on Dell's supported list for this board. I imagine the BIOS needs to be able to recognise the CPU...  or does it?  Perhaps some have common, or common-enough settings?

The closest thing I have to what is in that list is a Pentium G640T here (identical to the G620T in the list but with a slightly higher clock) maybe it is worth trying?

If the BIOS support is not there, are there any workarounds- or a way to ask Dell to fix the issue?

If the system won't be doing much work, leave the existing CPU in there -- though it draws 77 W at full blast, it will draw as little as a fraction of that when it's idle.

@ejn63: True- but only partly. As I understand it, at low utilisation any CPU will use a lot less than its rated power.

The main difference with all these cheaper ones is the number of cores, I need no more than 2- so having any more (say 4) can double the baseline usage of the CPU.

Main thing for me is noise, if I can keep CPU power down I can avoid the fan turning on altogether, The reduction in consumption, heat and internal dust are not just a boon, they increase reliability ten fold.

Hmm.. My best guess is if its not on the official list, it may not work.  Dell doesn't make a lot of their computers THAT upgrade-able.

Xeon's working usually requires chopping keyways from the socket AND Rewiring pins via flex circuit.

And no Xeon is supported.  

@Speedstep, thanks for commenting!

Do you remember in which cases? LGA 1155? i5/i7?

Or which chipset/s?

I am not looking to take it that far: Eg to fit a CPU not designed for this socket or that isn't on the Intel's H77 compatibility list.

Last year, on an old T430 workstation (this also worked on the Dimension 9200 tower), upgrading to a Xeon only required swapping in ECC unbuffered memory modules instead of the factory unbuffered DIMMs. And upgrading to 2.6/2.8G Q6600/Q6700 quad core CPUs only required swapping out the 1.8G Core2 Duo they originally came with.

IIRC, some got them running with the faster extreme quad core CPUs Intel made at the time.  Double the cores, double the speed... and the option of Xeon with no mods at all.

I imagine Dell just forgot to update the BIOS with these abilities.  But there are other things like thermal heat management that have to be considered as part of the change.

Right now, in this case with this H77-based board, downgrades may be even more easily overlooked by the team that look after board & cpu compatibility- for example of the board was being produced at the end of the architecture's lifecycle, they may have only tested the more recent CPUs and simply overlooked many of the older ones, or non-target market ones, that would or could work with it.

As I understand it from previous compatibility on other boards, If Intel says G620T should work, 640T may too- though only as a 620T.  Both processors are very similar to the Xeon E3-1220 v2- and its low-power version, the E3-1220L v2.  But may have to try with ECC RAM.  I have both types of RAM on-hand, but not a 20W E3-1220L v2, (I only have the 13W E3-1220L v3).

OK, so I have confirmed that BIOS A06 correctly recognises the 35W Pentium G640T processor, which is not on Dell's list of compatible CPUs.

Glad to have gone from a 77W CPU to a 35W one that I had, even if its a slow-coach in comparison to other 35W CPUs, such as the i5-3470T. It at least proves Dell's list is incomplete and at 2.4GHz 2 core, it does what I need for now. But processing capability is right down, as the original 77W i7-3770 had 4 cores at 3.4GHz.

Officially only 35W or higher TDP processors are supported, but now I have a little more hope. One day I'll come across a Xeon E3-1220Lv2 (17 or 20W TDP IIRC) and try it using ECC RAM.