Any idea why Intel skipped the 5xxx number range for desktop?

[mikeymikec]

It only occurred to me the other day that Haswell on the desktop was the 4xxx range, then its successor, Skylake, was 6xxx. Whereas on mobile Haswell was 4xxx and Skylake was 5xxx... I think?

 

[lolfail9001]

5775C and 5675C.

Broadwell was so late, it did not make sense for Intel to roll out a complete line-up, with Skylake few months away.

 

[richierich1212]

They released Broadwell on desktop i5-5675C and i7-5775C processors.

They were scarce as hell when released, and Intel was having 14nm delays at that time so they only released them to certain markets in the beginning. I was seriously looking at buying a 5775C from Japan for the first month because I just wanted to mess around with it and I could drop it into my Z97i-Plus motherboard

But I sure as heck wasn't going to pay $400+ when I got my 4790K for $280 a year earlier.

 

[mikeymikec]

Thanks, that makes sense.

 

[Obvcop]

I managed to pick up an entire 5775c itx system on ebay for £400, ended up throwing in a gtr 480 and giving it to a friend. Such a good CPU, I wish they would have used the EDRAM on other desktop CPU's and not just mobile. It makes a really decent APU as well.

 

[Arachnotronic]

5775C and 5675C.

Broadwell was so late, it did not make sense for Intel to roll out a complete line-up, with Skylake few months away.

Intel never planned for a complete Broadwell lineup for desktops, delays or no delays. They were never on the roadmap.

 

[lolfail9001]

Intel never planned for a complete Broadwell lineup for desktops, delays or no delays. They were never on the roadmap.

I am not claiming Intel cancelled it either, i am just saying that once they realized that Skylake would be almost ready by the time 14nm is functional, there would be no point in doing extensive roll-out of Broadwell.

Similar thing that is rumored to happen with Cannon Lake, ain't it.

 

[Arachnotronic]

I am not claiming Intel cancelled it either, i am just saying that once they realized that Skylake would be almost ready by the time 14nm is functional, there would be no point in doing extensive roll-out of Broadwell.

Similar thing that is rumored to happen with Cannon Lake, ain't it.

There were Cannon Lake-H/S chips on the road-maps from the beginning, they were only cancelled & replaced with Coffee Lake about a year ago because 10nm yields are currently in the toilet and Intel knew there was no chance of having those chips ready in time.

 

[Shmee]

I have a 5930k

 

[jihe]

They didn't.

 

[Sheep221]

Intel never planned for a complete Broadwell lineup for desktops, delays or no delays. They were never on the roadmap.

This, they designed platform enitrely around mobile segment, even desktop CPUs are low power upto 65w

 

[ZGR]

This, they designed platform enitrely around mobile segment, even desktop CPUs are low power upto 65w

But the 65w C series can have all the power savings options disabled, and can be overclocked. But yes, it was definitely designed around mobile. It caps around 4.2 GHz at ~1.3-1.4v; although I am still unsure if this is a broadwell limitation. It needs a lot more voltage to get above 4.2-4.3 GHz.

 

[mikeymikec]

I just looked up whether the 5775C is compatible with my board, then remembered that I don't want to have to go through the hell that was the installation process of my HSF.

The 5775C was the one with the absurd amount of cache wasn't it?

How come it lists it in the graphics category? I thought it was a CPU cache rather than graphics RAM or something.

https://ark.intel.com/products/88040/Intel-Core-i7-5775C-Processor-6M-Cache-up-to-3_70-GHz

 

[LTC8K6]

I just looked up whether the 5775C is compatible with my board, then remembered that I don't want to have to go through the hell that was the installation process of my HSF.

The 5775C was the one with the absurd amount of cache wasn't it?

How come it lists it in the graphics category? I thought it was a CPU cache rather than graphics RAM or something.

https://ark.intel.com/products/88040/Intel-Core-i7-5775C-Processor-6M-Cache-up-to-3_70-GHz

Wiki:

The 128 MB of eDRAM in the Iris Pro GT3e is on the same package as the CPU, but in a separate die manufactured in a different process. Intel refers to this as a Level 4 cache, available to both CPU and GPU, naming it Crystalwell.

 

[mikeymikec]

Is it still available even if the GPU isn't in use (ie. discrete graphics in use instead)?

I should probably stop being silly by thinking how awesome it would be to have a 128MB L4 cache and lusting after it for my own machine.

 

[ZGR]

Is it still available even if the GPU isn't in use (ie. discrete graphics in use instead)?

I should probably stop being silly by thinking how awesome it would be to have a 128MB L4 cache and lusting after it for my own machine.

It's pretty cool, but not noticeable in most scenarios. I bought it for gaming and it is great in Fallout 4 with lots of mods. But how great is it vs a 5.1 GHz 7700k with fast DDR4? Probably loses; but I honestly don't know. Frametimes? I want to believe the cache helps in a lot of games, but I only game at 60 fps so I am always GPU limited anyways. I usually play RTS games and games with lots of AI so the CPU's cache is usually thrashed. The L4 as a victim cache makes a ton of sense on paper, but no tool exists to see it work in action.

I love the concept and will be hanging onto it until Intel releases another unlocked i7 with an L4 cache (RIP). That won't be happening any time soon I bet.

BIOS compatibility is a nightmare. Don't jump into it blindly and don't use DDR3 above 2400 MHz. I use 2400 MHz CL10 and I had to raise my core voltage substantially from 2133 CL12 at 4.2 GHz to maintain stablity.

I use L4 with the iGPU disabled just as the victim cache. My BIOS cannot disable the eDRAM despite having the option to in settings. I have to flash back to an unsupported BIOS to disable the eDRAM.

TL;DR: Don't do it

 

[Azuma Hazuki]

It sounds like they didn't quite intend that one to get out into the wild. Maybe they didn't expect what's effectively a Level 4 cache to be as useful as it was?

 

[ZGR]

It sounds like they didn't quite intend that one to get out into the wild. Maybe they didn't expect what's effectively a Level 4 cache to be as useful as it was?

I think the big problem was the latency. It has great bandwidth, but latency is really all that matters in games, and high speed DDR4 is a bit better in regards to latency.

 

[mikk]

I think the big problem was the latency. It has great bandwidth, but latency is really all that matters in games, and high speed DDR4 is a bit better in regards to latency.

It's the other way around, latency is great on Intels L4 compared to DDR4 but the bandwidth itself isn't that special.

 

[tamz_msc]

With fast DDR4 and tight timings you can reach comparable performance with the EDRAM on both latency and bandwidth. It helps the iGPU more than the CPU.

 

[lolfail9001]

It's the other way around, latency is great on Intels L4 compared to DDR4 but the bandwidth itself isn't that special.

Even latency is not anything special on Intel's L4, it's like 40 ns, Skylake hits that with any B-Die kit on tighter timings.