Does the Late 2015 iMac Have a PCI-e 3.0 Bus?

Welcome to the Apple Support Communities.

No. What are you trying to accomplish?

Cheers,

Jack

Alvin777 wrote:

Hi. How about for the 2017 iMac? Is it a PCIe 3.0 x4 lane bus still or PCIe 4.0 x16 lane bus (hopefully coz' 2017 is 7 years after 3.0 was launched)?

There’s no PCIe slot in any iMac.

2017-era iMac and iMac Pro models had Thunderbolt 3 for external expansion, with two Thunderbolt 3 connections on most and four connections on iMac Pro.

Typical internal storage connection was 6.0 Gbps Serial ATA (SATA), 1 - 8.0 GT/s NVMe PCIe x4.

Download the MacTracker app from the App Store and explore..

Is this the info you need?

Alvin777 wrote:

Thanks for the info (it's nice to know more about a product, the more one knows the more one loves and admires it). It's nice the 2017 iMac has PCIe 4.0 x4 lanes (why don't they use a x16 lane for the bus?)

There’s no PCIe bus with available slots, and x4 works fine for what was needed. x16 would be for a fairly serious (internal) I/O connection, or an (another) internal GPU. Neither of which was a target for iMac, or particularly fits in the shell.

Need lots of bits, connect to Thunderbolt external.

What's the read speed then of the Apple Blade (correct me if I'm wrong Apple's NVME SSD equivalent is called Blade?) 1TB and higher TB that are factory installed in the 2017 iMacs?

Run some web searches for imac nvme ssd or similar search targets via DuckDuckGo or such, and see what shows up. Found some fairly detailed discussions that way. OWC seems to have had some options there, too.

Can you please explain what you’re trying to accomplish?

The 2017 iMac has this:

From the MacTracker app

No slot but evidently a buss is PCle x4. Is that what you're asking about?

.

There are no PCIe slots available within an iMac.

The available PCIe (external) connection is Thunderbolt, with two Thunderbolt 2 connections (2 by 20 Gbps) available across the various iMac late 2015 models I’ve checked.

There are Thunderbolt 2 NVMe enclosures around, not that there have been many discussions of those enclosures around here, and not that I’ve tried using one with this configuration.