Dell Latitude E5420 CPU upgrade

Hi guys.

I've got a used E5420 laptop which I am currently using until I can find a replacement for my Acer Helios 500 PH517-61 (all AMD hw) which bit the dust after a latest BIOS update (done correctly) corrupted the BIOS and ended up being 'repaired' for over 1 month with no end in sight (and because they failed to repair it up to 28 days, I was offered a refund or a replacement - but there is no viable replacement in UK for the Helios 500 in the same price range with those kind of specs and cooling - and I'd prefer avoiding Intel).

So, as a temporary backup, I'm currently using the E5420 I got from someone a while back.
It originally came with i3-2310M cpu. Has a G2 Socket (Socket 988B rPGA).

I wanted to upgrade the unit for a low amount of money to 'tie me over' until I can get my refund and find a suitable replacement.

I checked online on compatibility of this socket and various CPU's.
There is a Sandy Bridge i7-2720QM which is quad core... but that CPU is 45W, and the E5420 came with i3-2310M which is 35W.
So, I'm not too sure if the cooling in the unit would be able to handle a 45W CPU (otherwise I do think the 2720QM would work in the laptop as I think someone else upgraded that succesfully... but they didn't show what the thermals are like, only that the CPU works)... unless you could provide me with some info that the cooling could handle the 45W.

Otherwise, I also looked into i7-3612QM. It's a 35W quad core Ivy Bridge CPU which also has a better IGP (maybe not by a lot, but still) ... that would be a 'perfect' replacement, and its compatible with the socket in E5420.
Now, question is, would the 3612QM work in the E5420?

The latest BIOS for E5420 is A14 which was released in 2014 and I have it installed on this E5420.
The 3612QM was launched in 2012.
So, there's a chance the microcode supports it (if Dell included it)... and if someone has info on this, I would appreciate it.

If not, I might get the SB quad in that case (provided the unit can handle 45W)... or a more powerful SB dual core.
However, I don't see too much point in updating from 2c i3 to 2c i7... the differences in clocks aren't too huge and the performance impact would be relatively small if I'm not mistaken.

 

Ah my favorite design from these models...

3rd gen CPUs will not work despite the same socket.

Officially supported CPUs:

PRC,B710,1.6,SNB,1C,J1,P
PRC,B800,1.5,SNB,2C,Q0,P
PRC,B840,1.9,SNB,2C,Q0,P
PRC,I3-2310M,2.1,2C,SNB,J1,P
PRC,I3-2330M,2.2,SNB,2C,J1
PRC,I3-2330M,2.2,SNB,2C,J1,P
PRC,I5-2410M,2.3,2C,SNB,J1
PRC,I5-2410M,2.3,2C,SNB,J1,P
PRC,I5-2430M,2.4,SNB,2C,J1
PRC,I5-2430M,2.4,SNB,2C,J1,P
PRC,I5-2520M,2.5,2C,SNB
PRC,I5-2520M,2.5,2C,SNB,J1
PRC,I5-2540M,2.6,2C,SNB,J1,P
PRC,I7-2620M,2.7,2C,SNB,J1,P
PRC,I7-2640M,2.8,SNB,2C,J1
PRC,I7-2640M,2.8,SNB,2C,J1,P
SVC,PRC,I3-2350M,2.3,SNB,2C,J1
SVC,PRC,I5-2540M,2.6,2C,SNB,J1

Unofficially I have only seen 2720QM working:

2820QM:

So I can say look for a 2720QM or 2820QM whichever is cheaper.

 

From experience you can try every sandy bridge cpu on this laptop, even an XM one should work but the cooling will not follow the load

 

Yeah... no XM... that would likely be too much.
It would be nice to have a quad core inside (in this case 2720QM would be the better choice as it would be cheaper and only 100MhZ lower than 2820qm - plus as a result, maybe a bit lower thermals by default if that video of 2820qm in E5420 is any indication).

That said, there's also the option to undervolt 2720qm too and ensure lower temperatures.

Plus, I was also planning on upgrading the RAM to 16GB and SSD to 500GB... all in all it would come to about £160 for complete set of upgrades.
I can handle that and I can keep this laptop as a 'backup' just in case once I finally get a new laptop.

 

Nope, not on mobile Sandy Bridge. Haswell was the first gen with voltage control.

 

Ah I see.
Well, either way, I pulled the trigger on 2720qm, so I'll test it out in my system.
If it overheats after continuous testing (or give it a week or so) I'll return it and get i7-2620M most likely.... but if the 2820QM test in E5420 is any indication, I think 2720qm will be fine for what I need it.

SSD will be here tomorrow and CPU on Wednesday.
Will keep you guys posted on the upgrades in case you're interested.
I still have the RAM to upgrade to 16GB, but that will probably wait a couple of weeks.

 

You can probably also use ThrottleStop to adjust the power limit down to 35W if need be.

 

That would certainly keep the temperatures in check... but would that result in much performance loss?
I take it this would require of the CPU to downclock itself.

 

Just be sure to use a decent thermal paste and go from there.

Throttle stop can be used to lower TDP and even the turbo ratios.

At the end of the day you have two more cores, 4 mores threads, it will still run faster than the dual core.

I am sure your CPU will run within spec in that laptop.


Side note: I am surprised we haven't seen a Helios 500 R2 with 3900X and RX 5700 XT yet.

 

The degree of downclocking or performance loss will depend on how strenuous the workload is. Since power varies quadratically with voltage, shaving off 10W shouldn’t result in a large drop in voltage/frequency.

 

I will use GC Gelid Extreme thermal paste (its one of the best cheapest ones).
I was potentially thinking on using Kryonaut, but I already have Gelid Extreme on hand.

As for Acer making Helios 500 R2... 3700x and maybe 3900 as both are in 65W TDP range (though the Helios 500 cooling could certainly handle 105W TDP CPU easily - alas I don't think Acer would try it).
And 5700XT... perhaps. Vega 56 was 210W TDP while 5700XT has 225W TDP.
However Acer could likely bin it down to 120W-135W TDP like they did with Vega 56 and keep it within 5-10% of the desktop part (much like V56 in Helios 500 was).

As for why the Helios 500 R2 wasn't released yet... possibly because it took several months (almost half a year) for Asus and Acer to release Zen desktop replacements. They may be waiting to see how popular those components are and could also be waiting for prices to come down (for themselves obviously).

It would certainly make my choice a LOT easier and would provide a really great boost in overall performance/efficiency over the original Helios 500 (which is no longer selling in UK) if I knew Acer was going to make it.

However, we don't even know if Acer will make a revision with Zen 2 and Navi (and use same/similar cooling).
I hope they do... but if so, they either need to only have 2 RAM slots in the mobo, or 4 of them like now... but all 4 should be on the easily accessible side of the laptop (which doesn't require full disassembly).
And an unlocked BIOS would be nice (or at least one with no RAM speed limitations like they placed them on this Helios 500).

 

i7-2720QM arrived (with 2 slightly bent pins no less - enough to obstruct the CPU going into the socket), so I had trouble putting it in until I managed to correct the pins.
I did consider returning the CPU because of the bent pins, but since I managed to correct them and CPU is running fine now... is there a possibility of this causing some problems in the future if I have no plans of removing the CPU from the socket?
I don't think there should be, but I'd appreciate other people's thoughts on this.

Used GC Gelid Extreme, was quite painless to apply etc.
System fired up and works without any problems.

I DID notice the 2720QM iGP is running FAR smoother now (in a few online games i play daily) in comparison to before.

Temperatures appear stable thus far (a bit cooler vs i3 actually), but I have yet to put this thing through its paces, and the i3 had an OLD thermal paste application on it... so GC Gelid Extreme might take a bit of time to cure and temps to settle down further.

The fan still shuts off when CPU isn't noticeably in use... so that carried on nicely from i3 (looks like the HDD was initially contributing to higher temps in the system, so upgrading to the SSD was sensible in regards to system snappiness, temperature, etc.).

The only thing left to upgrade is the RAM (to 16GB), but that will have to wait a week or two.
Already the laptop feels its a lot more capable... and a sensible temporary replacement I can use for college until I can find a Helios 500 Ryzen/Vega to buy again once my refund comes through, or wait for Zen 2/Navi revision.