Dell Pro Max 16/18 Plus (2025 model) pre-release discussion — MB16250, MB18250

[MyPC8MyBrain]

1 hour ago, AL123 said:

why not go with the longer 68mm dual channel module

i believe heat was the issue with the larger modules, 
 

[AL123]

2 hours ago, MyPC8MyBrain said:

i believe heat was the issue with the larger modules, 
 

Yeh just seems odd that the engineering to create a 2 slot single Channel stacked arrangement was easier than cooling a single 256GB dual channel module. 
 

it does open up even larger quantities in future but don’t think the market for 128GB is huge let alone 256GB or 512 GB 

[MyPC8MyBrain]

39 minutes ago, AL123 said:

don’t think the market for 128GB is huge let alone 256GB or 512 GB 

not to mention most of this is not supported by current and likely next gen mobile CPU IMC's to begin with,
these are "LaLa Land" numbers, by the time these will be a reality this platform will be too old to even get driver updates,
pointless cramming into this particular platform generation imho.

[AL123]

12 hours ago, MyPC8MyBrain said:

not to mention most of this is not supported by current and likely next gen mobile CPU IMC's to begin with,
these are "LaLa Land" numbers, by the time these will be a reality this platform will be too old to even get driver updates,
pointless cramming into this particular platform generation imho.

The official specs of the core ultra HX series definitely support 256GB, but sure it will be niche for a while yet. 

 

512GB wouldnt seem to crazy for future with the AI focus especially if these CAMM modules end up on DDR6 desktops atleast they are planning ahead. I think they need speed parity with soldered to really gain ground though. 

Dell do seem cautious even on the pro Max tower T2 desktops we use featuring core ultra CPUs they max out at 128GB currently.
 

On desktops I suspect some of that is to try and push to higher priced workstation platforms but the sapphire rapids Xeons are very poor performance wise.

 

the Precision 7875 is the only one we will consider and it just got an update to Zen 5 threadripper Pro 9000. it didn’t even get a name update let alone pro max rebrand, maybe Intel bias is still present. 
 

I’m going to test out the base pro max 16 with AMD CPU’s but the graphics cards top out at RTX 1000 Blackwell which is a bit low for most of our users and the RAM is soldered which we try to avoid. 
 

Hopefully see some AMD competition to the core ultra K desktop and core ultra HX based systems next gen Dell workstations

[MyPC8MyBrain]

11 hours ago, AL123 said:

The official specs of the core ultra HX series definitely support 256GB

i was looking at Intel® Core™ Processors HX-Series (14th gen) brief specs,
interesting, the Ultra Core for Desktop processor is showing 192GB limit with 2 memory channels only
while the Core Ultra Mobile 285HX is Listing 256GB limit still with 2 memory channels,

CAMM's 4 channel is still in the air outside of Dell's marketing bubble,
until CPU's ship with 4 IMC's CAMM's are pointless atm.

mobile platforms with these processors onboard will never be able to utilize CAMM's 4 channels as the CPU is soldered to the board, since the premises of CAMM is quad channel, the tech currently embedded is moot. 

[AL123]

3 hours ago, MyPC8MyBrain said:

i was looking at Intel® Core™ Processors HX-Series (14th gen) brief specs,
interesting, the Ultra Core for Desktop processor is showing 192GB limit with 2 memory channels only
while the Core Ultra Mobile 285HX is Listing 256GB limit still with 2 memory channels,

CAMM's 4 channel is still in the air outside of Dell's marketing bubble,
until CPU's ship with 4 IMC's CAMM's are pointless atm.

mobile platforms with these processors onboard will never be able to utilize CAMM's 4 channels as the CPU is soldered to the board, since the premises of CAMM is quad channel, the tech currently embedded is moot. 

sorry forgot to put a link but officially specs I was looking at are here, I think these may have changed after the launch. pretty sure that happened before when 48GB dimms became available there was a subtle update of the product pages to show and increase from 128 to 192 GB

 

 https://www.intel.com/content/www/us/en/products/sku/241060/intel-core-ultra-9-processor-285k-36m-cache-up-to-5-70-ghz/specifications.html

https://www.intel.com/content/www/us/en/products/sku/242297/intel-core-ultra-9-processor-285hx-36m-cache-up-to-5-50-ghz/specifications.html

 

Suspect we will always be limited to dual channel on Intel core CPUs to segment the market/ keep prices reasonable, same for AMD Ryzen as far as I know and intel seem to have abandoned high end desktop CPUs. AMD technically have them with threadripper non pros but cpu and motherboard prices are high.

 

I hadn’t really seen quad channel as a potential advantage of CAMM.

 

Until dell shared details of the 256GB option i’d always seen it as a single dual channel card as its primary advantage. saving space vs so-DIMM and an alternative to soldered memory that will allow for higher speeds while being upgradable/ replaceable.
 

Making it a 2 module system just doesn’t make much sense for me on laptops at least seems needlessly complicated. 
 

to be honest for our use it might be moot anyway, when we get to 256Gb or more for us we are usually looking at massive FEA/CFD simulations where it is more memory bandwidth sensitive anyway. for these Threadripper Pro is our current choice all the memory/ bandwidth you could want! , hoping Intel will come back with something competitive next gen to compete, much as Intel had dominance in data centre and high performance cpu compute for years AMD are so strong current that I worry for Intel now! 

 

 

 

[win32asmguy]

2 hours ago, AL123 said:

I hadn’t really seen quad channel as a potential advantage of CAMM.

 

Quad channel here is a bit misleading as it's two 32bit subchannels with ddr5 instead of DDR4 which had a single 64bit channel per module.

 

CAMM's advantage will be better signal integrity over sodimm or csodimm even rivaling udimm. So 256gb might be stable at 5600mt at a given temperature compared to 4x64gb sodimm that may be stable up to 4000mt under the same conditions.

[SvenC]

My Pro Max Plus 18 shipped on 24th August from China to Germany - might arrive next week 🙂

 

RAM is already waiting 2x Kingston CSoDimm 32GB

[AL123]

15 hours ago, win32asmguy said:

 

Quad channel here is a bit misleading as it's two 32bit subchannels with ddr5 instead of DDR4 which had a single 64bit channel per module.

 

CAMM's advantage will be better signal integrity over sodimm or csodimm even rivaling udimm. So 256gb might be stable at 5600mt at a given temperature compared to 4x64gb sodimm that may be stable up to 4000mt under the same conditions.

Had to google that as been so long since I read anything about DDR5 standards but sounds like it is still 64bit total per module but split into 2x32bit 

Various articles say this should actually be better 

https://www.kingston.com/unitedkingdom/en/blog/pc-performance/ddr5-overview

 

i presume when CAMM is referred to as dual channel it is 4x 32bit sub channels? 
 

What you describe is what I am going for larger capacity but better speed than 4x SO-DIMM so manufacturers don’t tell us soldered is the only option for the future of high performance. Realistically it’s rare we upgrade but ram is one of the most common failures, not sure on soldered ram failure rates vs descrete dimms 

[addabis]

Is it stated somewhere whether the GPU (RTX5000 specifically) uses 8x or 16x PCIE 5.0?

[Aaron44126]

44 minutes ago, addabis said:

Is it stated somewhere whether the GPU (RTX5000 specifically) uses 8x or 16x PCIE 5.0?

 

Curious about this too. @AL123 Can you check? GPU-Z will report this under "bus interface".

[AL123]

On 8/23/2025 at 6:29 PM, win32asmguy said:

 

Thanks for your continued review / information! By chance would you be able to check HWInfo64 memory information page for detailed specs on the timings for both the CSODIMMs and CAMM modules? It looks like this:

 

 

That is from a non-CSODIMM Kingston Fury kit with tREFI tuned and at 1.25v. With SA Fabric and D2D tuned its around 90ns latency which while far behind a tuned desktop 285K is much better than most stock OEM shipping laptops. Some guys with Lenovo Legion 7i's have also hit close to 80ns as well. In theory a CAMM XMP module could do really well here if they offered single rank Hynix modules with desktop-grade timings.

Finally back in the office again image is is for pro max 18 plus with 2 x 64 CSODIMM

 

Expecting a unit with 128GB CAMM module in 1-2 weeks don’t have the other unit that had 64GB CAMM anymore 

 

[AL123]

1 hour ago, Aaron44126 said:

 

Curious about this too. @AL123 Can you check? GPU-Z will report this under "bus interface".

I only have Pro Max 18 Plus with RTX PRO 4000 Blackwell currently but screen grab attached. Will have an RTX5000 in the next 1-2 weeks 

Looks like x16 but let me know if there is another location to check 

 

 

[Aaron44126]

I think this is reporting that the GPU supports 16 lanes, but it is only running at 8 lanes (that "@8" at the end). The very low GT/s value would be because at the time that you took this, it was only running at low speed (PCIe1 or PCIe2?) because the GPU was not busy.

 

This makes sense, I can personally confirm that previous generations (Precision 7560 and 7770 that I have access to) only have 8 lanes for the dGPU. They moved from 16 lanes to 8 lanes at the same time that they moved from PCIe3 to PCIe4.

 

It wouldn't matter if it is a 4000 or a 5000 card. The limiting factor is the physical DGFF interface and motherboard layout. If Dell only ran 8 lanes for the dGPU, then that's that.

 

[Edit]

Tried to check if my Precision 7560 reports similarly but the security measures that they have in place now will not allow me to run GPU-Z. 😕

(That's my work system. None of my personal systems are running Windows anymore.)

[win32asmguy]

1 hour ago, AL123 said:

Finally back in the office again image is is for pro max 18 plus with 2 x 64 CSODIMM

 

Expecting a unit with 128GB CAMM module in 1-2 weeks don’t have the other unit that had 64GB CAMM anymore 

 

 

That is great to see gear 2 on the csodimms. Trfc is also good for jedec timings.

[addabis]

1 hour ago, Aaron44126 said:

I think this is reporting that the GPU supports 16 lanes, but it is only running at 8 lanes (that "@8" at the end). The very low GT/s value would be because at the time that you took this, it was only running at low speed (PCIe1 or PCIe2?) because the GPU was not busy.

 

I guess it's the CPU limitation on the number of lanes (24) and the presence of 4 M.2 slots.

ChatGPT even tells me that PCIE 5 is limited to M.2 slots, and the GPU would use PCIE 4 x8. I'm not sure if I can trust that.

[Aaron44126]

Somehow they managed 16-lane for the GPUs in Precision 7750 and earlier. Precision 7750 also had four M.2 slots.

 

The PCH does allow for some additional (shared-bandwidth) PCIe lanes. In the last few generations of systems, Dell has had one of the four M.2 slots attached directly to the CPU, and the other three routed through the PCH.

 

(Even though there aren't that many "slots" on the motherboard, there are a multitude of other devices that gobble up PCIe lanes — the Wi-Fi, Ethernet, and WWAN chips, the memory card reader, the sound chip, Thunderbolt ports, ...)

 

...Not that I really think that them having it limited to 8 lanes is a big deal. The performance impact on the GPU should be minimal. It is hard to push enough data to "need" 16 lanes of PCIe4 speed, and clearly you can keep the GPU busy (100% utilization / max power draw) with this setup. I think it would not be noticed so much in real-world situations but probably appears as a slight dip on GPU-heavy benchmarks.