this post was submitted on 08 May 2024
140 points (94.3% liked)

Technology

59648 readers
2653 users here now

This is a most excellent place for technology news and articles.

Our Rules

  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots

founded 1 year ago
MODERATORS
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
140
New Laptop Memory Is Here! LPCAMM2 Changes Everything! - iFixit Video (youtu.be)
submitted 6 months ago by [email protected] to c/[email protected]
22 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 10 points 6 months ago (2 children)

Yeah mega transfers. 1 transfer is 8 bytes. the DD in DDRX is double data so it can send 2 transfers per channel per clock. CPUs pretty much always use 2 channels, so the formula is just GBps = 32 * MT/s. My PC has 6000MT/s DDR5 in a dual channel config so thatd be 192GBps.

Idk how apple is getting above 300GBps, maybe theyre counting the integrated GPU as part of the total. GPUs often have 4 or 6 or 8 channels so thatd make sense...

[–] [email protected] 5 points 6 months ago* (last edited 6 months ago) (1 children)

Thank you for going into detail.

Okay so, 1 T = 8 B. DD => 2 T/channel. And with 2 channels we get 4 T, so 4 × 8 = 32. Okay I get you. Thanks so much. 🙂

Yeah that's a crazy number with 300-500 GBps if DDR5 is doing around 200... Absolutely insane actually. But yeah, good theory about the GPU. ~~Those bastards, padding the numbers.~~

[–] [email protected] 4 points 6 months ago (1 children)

I don't think its fair to call it "padding". They're on the same die anyways and share the same memory pool through the same connections, makes sense they all have the same speed. I imagine Intel/AMD CPUs with iGPUs also share memory speeds and are both limited to how many ram channels you have configured. Apple very much could achieve that kind of speed by having more ram channels. Have the ram working in quad-channel mode, and you double the 192 GBps to 384 GBps.

[–] [email protected] 1 points 6 months ago

Good points. I retract my name-calling!

[–] [email protected] 3 points 6 months ago

Anandtech has an article about the M3 and details about it's memory speed. M3 has 100 GBps, M3 pro 150, and M3 max 400.

So theoretically there's no stopping laptop manufacturers to have multiple LPCAMM2 slots to achieve such speeds, correct?