Predict: The Next Generation Console Tech

[Deleted member 13524]

XGP is GPU vendor specific ?

Not vendor specific, but exclusive to AMD. The first laptop to implement it was actually a Fujitsu-Siemens, before the divorce (which delayed the product itself so much that it might have thrown the technology into irrelevance).

LightPeak is multi-vendor and can subsume all connected devices (HDD, monitors, GPUs, memory, another CPU, etc.)

I don't know how 10Gbps can be efficiently used for all that, especially CPUs and RAM memory.

XGP was essentially a PCI-Express 2.0 8x connector, so 4Gbps total. The box with the external GPU also had a USB 2.0 controller with two ports.



I really hope lighpeak/thunderbolt gets standardized, though. I like the idea of being able to connect an external/modular graphics card to a laptop. Especially if eventually we get to buy full-sized cards and connect them to laptops through a powered external box or something.

But I won't fall into the mistake of being an early adopter like I did for XGP.

 

[patsu]

But I won't fall into the mistake of being an early adopter like I did for XGP.

Ah, the Apple MacBook Pro fans already went ahead of us. We should have a few millions out there in a year or two. Their implementation is copper-based. I'm really curious about the difference between Sony's LightPeak implementation and Apple's.

 

[Blazkowicz]

I don't think a computer interface will be successful if it's only available for the upper middle class and hipsters ; and advertised products I read about are video stuff in the realm of Matrox or Quadro, or SAN for content creation.

so probably the Thunderbolt will be alive and very useful in some niches, but I can see it being sidelined in a way similar to firewire, never see mass adoption and cheap peripherals.

 

[patsu]

I didn't know Thunderbolt is also supported on the iMac. Rumors on the street claim that the entire Mac line will support Thunderbolt by end 2011. According to these sites, it currently costs $100 to support Thunderbolt now. That's why you only see it on high end devices. The cost will drop in 2012.

Firewire and USB serve fundamentally the same needs. If Thunderbolt has very small latency and can interface with components not possible with USB 3.0, then it may be able to grow.

 

[SedentaryJourney]

Ah, the Apple MacBook Pro fans already went ahead of us. We should have a few millions out there in a year or two. Their implementation is copper-based. I'm really curious about the difference between Sony's LightPeak implementation and Apple's.

As far as I can tell Apple's version powers devices and is future compatible with optical cables. Don't know what advantage there is in going for a purely optical version.

 

[patsu]

Latency will increase with length for electrical lines. Optical should have shorter and consistent latency me think. Can't find any numbers. OTOH, electrical line can carry power (10W).

Also 10Gbps per channel in LightPeak/Thunderbolt (dual-channel, bi-directional) should be 20Gbps upstream + 20Gbps downstream = 40Gbps total.

 

[SedentaryJourney]

Latency will increase with length for electrical lines. Optical should have shorter and consistent latency me think. Can't find any numbers. OTOH, electrical line can carry power (10W).

Also 10Gbps per channel in LightPeak/Thunderbolt (dual-channel, bi-directional) should be 20Gbps upstream + 20Gbps downstream = 40Gbps total.

That's more a feature of the cable isn't it? Apple's port supports current copper cabling and future optical cables. It will also theoretically support copper/optical hybrid cables for charging. I don't see why Sony felt the need to fix what wasn't broken.

 

[rekator]

Ah, the Apple MacBook Pro fans already went ahead of us. We should have a few millions out there in a year or two. Their implementation is copper-based. I'm really curious about the difference between Sony's LightPeak implementation and Apple's.

You can have seven device chained in Apple implementation by thunderbolt port, Monitor, HDD, NAS, Etc…from different vendors.
On Sony you need their proprietary dock for extension, it's more a deported solution for extension than a proper extension port.
The Sony choose is very restrictive , ala Sony we can said.

 

[Shifty Geezer]

Latency will increase with length for electrical lines.

Do you mean due to lost packets and protocol to manage that? Because electrical signals travel worst case something like half the speed of light in usual cables, which is going to be fast enough to be effectively zero travel distance along even a few metres of copper cable - cable latency shouldn't be an issue.

 

[hoho]

At half the speed of light every meter adds about 7ns delay (at 3GHz one clock cycle takes ~0.3ns).

 

[Shifty Geezer]

At half the speed of light every meter adds about 7ns delay (at 3GHz one clock cycle takes ~0.3ns).

Firstly, half SOL should be worst case. I'd expect better efficiency - pure copper cables run at 90% propagation efficiency. So real additional latency should be minimal. Secondly, what are putting on this port that's going to be nanosecond-latency sensitive?! RAM is already offering as much as tens of nanoseconds latency. This is overcome with caching so we're not working live on slow RAM. If a difference between 8 CPU clock cycles transmission to receipt over optical, and 16 CPU cycles transmission over copper, is enough to impact your application, you'd have to be doing some freakily accurate and constant data serving! A GPU can be 1000 ns late in delivering a frame and the human viewer won't notice it, so I see no issues in having an external GPU that copies data across from on the main device, renders the visuals, and outputs back to the main machine for display. Given that copper can provide power as well, I don't see the reason to go optical only.

Like others though, I don't see the viability of these new protocols in a next-gen box when the devices will be pretty specialist. It makes some sense for things like laptops or tablets to connect expansion hardware, but for not XB3/PS4 where there'll be no point. Unless we finally consolidate all connectors into this one standard, doing away with HDMI and USB and network ports and connecting everything instead via a single port and connector system. That'd be quite cool, but I imagine if such a future ever happened it'll be well beyond next-gen, and maybe at a point where we no longer have individual boxes but just access the network a la OnLive.

 

[Deleted member 13524]

I guess optical cables in lightpeak should be used for fairly high cable lengths (tenths of meters), where impedance and external electromagnetic noise significantly affect the signal.

So thunderbolt is better for consumer applications (short cables, same-room connectivity) because of power transmission and lightpeak makes more sense for renderfarms.

 

[patsu]

That's more a feature of the cable isn't it? Apple's port supports current copper cabling and future optical cables. It will also theoretically support copper/optical hybrid cables for charging. I don't see why Sony felt the need to fix what wasn't broken.

Optical cable has 8ns latency for the last (7th) Lightpeak device. Electrical will have worse latency as length increase, especially after 3 meters.

According to original plan, optical Lightpeak can support up to 100Gbps compared to 10Gbps per channel. I don't know how well Sony's implementation performs.

You can have seven device chained in Apple implementation by thunderbolt port, Monitor, HDD, NAS, Etc…from different vendors.
On Sony you need their proprietary dock for extension, it's more a deported solution for extension than a proper extension port.
The Sony choose is very restrictive , ala Sony we can said.

Optical line doesn't supply power, so they need a dock to provide power to traditional devices. The dock also charges the laptop. It may be possible to hook up other LightPeak device to the chain if it doesn't need power. Should be cheaper and less cluttered to have a dock for multiple standard devices compared to several housing for GPU, memory, USB peripherals, etc.

Adapters can be used for the different connector. I suspect they chose USB 3 connecter on the 13" laptop to save space as you'd need minimum 2 USB ports for a laptop.

 

[Shifty Geezer]

Optical cable has 8ns latency for the last (7th) Lightpeak device. Electrical will have worse latency as length increase, especially after 3 meters.

How is latency a problem? You could stick an amp on the end of a chain with...100ns latency and the audio lag will be unnoticeable - absolutely nothing compared to the lag introduced by the processing elements. What situations can you envisage where a few extra ns of latency over cable will prove a problem that needs solving with optical connects?

 

[patsu]

I am not sure yet. Still gathering info. Not much is known about Sony's implementation. The Thunderbolt cables have chips inside to moderate and mux/demux the electrical transmission. I don't know if the optical version needs it.

EDIT: Coincidentally, Apple filed a patent on location-based docks:
http://www.appleinsider.com/article...pt_has_unique_profiles_for_home_work_car.html

 

[rekator]

With Thunderbolt you don't need a "specific" dock, a monitor with two port is a dock, a NAS with two port is a dock, etc…

 

[patsu]

But of course. You'll need Thunderbolt adapters to talk to each traditional device (USB, HDMI, FireWire, ...) though. With a hub or dock, You use up one Thunderbolt device to connect to multiple traditional/existing devices at the same time. In theory, you can have 6 more free slots for other Thunderbolt devices.

 

[Blazkowicz]

you might do funny stuff, such as multiseat, imagine daisy-chained boxes with a graphics card (even just a 2D one, or something like a PowerVR GPU), four USB ports, line out/mic in, whatever fancy you like (smart card reader, SD port, PS/2 port).

here you get additional seats in a very clean, low latency way.
microsoft already supports it with "Windows Multipoint Server 2011" (for now it"s done with USB boxes. yuck!)

it's vulnerable to a "breaking the daisy chain" attack from a rogue user but that's not too bad.
I wonder what can happen with a rogue peripheral.

oops! we're on a console thread!
well TB would allow some more advanced, but wired kind of WiiU controller.

 

[patsu]

>_< You don't need a "software server" to do LightPeak/Thunderbolt daisy chain, or dock. It may/will introduce more latency for a near real-time app like games.

 

[ninelven]

People typically game on servers with 20-100 millisecond pings. QED.