Question regarding cat 8 and adapters.

[kingwolf1989]

So im super confused here, apparently ive been out of the networking loop alot longer then i thought lol. So how come there are cat 8 cables that can do up to 40 GB/s but the fastest adapters are like 10Gb ones and they still use a fiber like adapters right? like what adapters or switches do you even use to get the 40 Gb speeds??? any and all information would be appreciative!

[Blue4130]

27 minutes ago, kingwolf1989 said:

So im super confused here, apparently ive been out of the networking loop alot longer then i thought lol. So how come there are cat 8 cables that can do up to 40 GB/s but the fastest adapters are like 10Gb ones and they still use a fiber like adapters right? like what adapters or switches do you even use to get the 40 Gb speeds??? any and all information would be appreciative!

Forward thinking. Right now you can only get 10Gbe on cat8, but I would not be surprised if someone comes out with a qsfp+ to RJ45 transiever. Then your cat 8 40Gbe could be useful.

 

Also, there are quite a few switches that can do 40Gb, that is actually not even that fast these days for enterprise. Mellanox is is up to 400 if I recall correctly.

[Electronics Wizardy]

There are standards for 25 and 40gb base t that would use cat 8, but I don't know of any hardware using this standard currently. There is also no garantee that those devices will ever exist. And 25 and 40gbe is likely to run pretty hot, and cat 8 costs more than om3/os2 fibre, so I don't see a reason to use those standards. And I'm guess for client use 10gbe will be plenty for a long time. Seeing that 4k online video is about 50mBit top,  files will need to be much bigger to take advantage of > 10gbe speeds.

[LAwLz]

On 8/14/2022 at 5:13 AM, kingwolf1989 said:

So im super confused here, apparently ive been out of the networking loop alot longer then i thought lol. So how come there are cat 8 cables that can do up to 40 GB/s but the fastest adapters are like 10Gb ones and they still use a fiber like adapters right? like what adapters or switches do you even use to get the 40 Gb speeds??? any and all information would be appreciative!

It's a chicken-and-egg problem.

 

The standards for 25Gbps and 40Gbps over Cat.8 copper cables exists. They are designed for data centers and not for office wiring (because they are limited to 30 meters).

I don't think any equipment exists that uses those standards, but the standards has to come first otherwise manufacturer can't build equipment around it.

 

I don't think 25Gbps or 40Gbps over copper Cat.8 cables sounds like a good idea though. Even in limited situations like in data centers. Just use fiber.

[Lurick]

4 minutes ago, LAwLz said:

It's a chicken-and-egg problem.

 

The standards for 25Gbps and 40Gbps over Cat.8 copper cables exists. They are designed for data centers and not for office wiring (because they are limited to 30 meters).

I don't think any equipment exists that uses those standards, but the standards has to come first otherwise manufacturer can't build equipment around it.

 

I don't think 25Gbps or 40Gbps over copper Cat.8 cables sounds like a good idea though. Even in limited situations like in data centers. Just use fiber.

Correct, no copper based 25G or 40G gear exists on the market, I've even asked and nobody seems to be looking to develop anything either. If anything were to come though it would likely be 25G first but I doubt there would ever be a copper SFP28 for it, it would just be fixed modules instead due to the increased heat requirements. 10G SFP already uses 2.5+ watts compared to less than 1 watt for 10g fiber modules.

[kingwolf1989]

ahh okay, thanks guys. I was like what in the hell, id think theyd have adapters that could make use of it before making, probably explains why theyre relatively inexpensive because there really isnt any adapters out there to take advantage of it right now.