256GB of RAM is Possible in z420 (continued)

[SamirD]

So continuing the original thread here:

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/256GB-of-RAM-is-Po...

The question asked in the above thread was:

"Would you mind posting the particular RAM cooler you found to work so well, and maybe even a picture of it in place.  I assume you left the "rear" memory bank of 4 sockets cooled by the HP RAM cooler.  Does the RAM cooler you got only cool the "front" bank of 4 sockets?

Here is a little article on RAM coolers for others:

https://graphicscardhub.com/ram-cooler-heatsink/"

I can't remember the exact cooler I got now, but those in the linked article are exactly the same style as what I used and they did the trick.  I left the rear bank to be cooled by the factory cooling and the new cooler only cools the front bank.  Hope this helps anyone trying to push 256GB!

And I believe there may be even more potential--512GB using 64GB LRDIMMs.  These are really expensive right now, but maybe 10 years from now they will be cheap enough to try. 🙂

[SDH]

SamirD,

Good to hear from you again.  I'll get a picture of the Z420 uploaded shortly to this thread showing how easy it is to install one of the Z440 double fin surface area larger heatsinks over the Z420 processor.  No modifications are needed as you'll see.

Going back to the Z420 memory cooling air duct that uses the fan action from the HP power supply to pull cool air in from the front over the "front" set of 4 memory slots and then up and out the rear... you may know that almost all of the HP parts from this time frame have two part numbers.  An "assembly" part number and a "spares" part number.  The assembly part number often is molded onto a surface of the part.  The spares part number may be on a sticker attached to the part but often not.  Two numbers for the exact same part.  Because it is generally easier for an eBay seller to find the assembly part number just by looking at the part this number is more often seen in the eBay listing.  Hence, the assembly part number for the air duct for the Z420 is easy to find via 663070-001, versus the spares part number of 663346-001.  Some sellers take advantage of buyers without this knowledge, as you'll see below:

This price contrasts with about $28.00 USD currently on eBay if you search for the correct number...

[SamirD]

Great to hear from you again too! 🙂  Can't wait to see the pics as that will really help visualize it.

Yep--IBM does the same thing, lol.  They have FRU and CRU numbers for the same part.

[banhien]

@SamirD 

Please use the following guide

          http://ntsizing.external.hp.com/drvlib/docs/Z420_Memory_Configurations.pdf

In 10 years time, who is going to keep the machine ? I worked in a big mainframe shop before and we replaced machines every 3 years or less.

Regards.

[SamirD]

You can use that guide if you want.  I'm going to enjoy more memory. 🙂

Secondhard hardware can have an extended life if they can do more than what their specs say.  Right now 512GB of ram is a lot even for servers, and the advantage of being able to have this much memory in a compact quiet tower has a lot of applications that HP never thought of--especially when these systems are cheap because they're old.  The current confirmed 256GB limit is second only to the 288GB in my Dell R710 server, which is a lot larger and more expensive machine with much different physical characteristics.

[SDH]

SamirD,

Agree with you, plus there is the sport of it.  And, the poster above provides outdated information from early 2012.  That is from before the Z420 v2 workstations were released.  There are more recent official HP guidelines for the v2 workstations that I have posted about multiple times here, and even they don't include information about use of the HP Z620 v2 certified fastest ECC buffered 1866 memory in the Z420 v2 workstations, which we have validated.  That works because the ZX20 v2 memory controller hardware is identical between the two.  You, however, have gone even further....

You'll be interested to know that the Z440 CPU heatsink/fan fits perfectly atop the Z420 CPU socket and there is no need for any modification to any HP parts around this significantly higher cooling capacity HP part.  I used to think that I needed to put on a fan from a Z420 CPU heatsink because the Z440 fan header has 6 instead of 5 pins.  Then I realized that #6 is just a ground jumper from pin 5, which is fed from pin 1.  That 6th pin socket just needs to hang out in space for 1/8" over the Z420 motherboard, as shown in the picture below.  Easy solution there...

The front memory cooling airflow guide is what I use.  You might be able to MacGyver on your memory cooling fan(s) to the top surface of that guide and drive the airflow downwards through a hole-saw hole in that black plastic surface so the increased airflow goes up and out via the power supply fan pathway as HP intended with this option.  Those are easy to see on eBay for project planning if you want.  For you cooling is paramount!

[SamirD]

Yep, there is a certain satisfaction in pushing something to its limits and beyond, and is very akin to motorsports, which is something I also enjoy. 😄

Thank you for all the great part numbers and pictures. 😄 This makes is really easy to visualize everthing. I remember you posting about that cooler and the huge upgrade that it is. With my current cpu it doesn't make any sense (E5-2630L), but if I upgrade to something with a higher tdp, the z440 upgrade makes perfect sense as a wonderful bolt-in.

The heat that comes off the memory was pretty intense during the memtest and it made more sense to have it vent into the case where the rear fans can pull it out that way since I have all fans set to 100%. I considered getting the front memory cooling guide, but knowing how much additional heat would be forced through the power supply, I know it would probably shorten the life of the power supply.

I haven't started taxing the memory yet as I haven't installed proxmox on it yet and made it part of a cluster. I plan to have my z420, z600, DL380 G5 x2, DL360 x2, Dell r710, r410, 2950 x2, cs24 all part of this cluster. It will be interesting to be able to run more virtual desktop instances than I will know what to do with. 😄 And I'll be able to see how the cpu makes a difference in performance. And then spring will come and I will have to turn almost all of it off because of the heat, haha.

[SamirD]

So someone who was trying 256GB in a v2 motherboard was having problems with the memory not being recognized.  They were using a 1650 v2 processor.  After a bunch of research, they discovered that LRDIMM support was dropped from the 1650 v1 to the 1650 v2.  In my setup I have an E5-2630L v1, so this is an important caveat!