HyperTransport 3.0 Ratified 179
Hack Jandy writes "The HyperTransport consortium just released the 3.0 specification of HyperTransport. The new specification allows for external HyperTransport interconnects, basically meaning you might plug your next generation Opteron into the equivalent of a USB port at the back of your computer. Among other things, the new specification also includes hot swap, on-the-fly reconfigurable HT links and also a hefty increase in bandwidth."
So the CPU will still be waiting for RAM? (Score:2, Interesting)
External FGPA units? (Score:3, Interesting)
This can only be a good thing.
Re:So the CPU will still be waiting for RAM? (Score:3, Interesting)
Sure, with it there would be a possibility of cache coherency issues while without there would be a performance hit whenever something hit the bus...
I guess it'd depend on the cost of ram when building such a device... I'm guessing that a whopping 64-128 meg cache aught to be enough for sometime.
Re:Hmmmm. (Score:3, Interesting)
Lets say your company has a 4-way hub that can be plugged into the system of choice... imagine the cooling such a thing would require in order to keep from burning up in its enclosed plastic or (more likely) metal box.
Not to mention the noise... oh good god the noise. My dual core 3800+ at home is quite loud... I can only imagine what a few of those bad boys sitting on your desk would sound like under full load.
I suppose a good deal of issues could be eliminated if low power cpu's were to be used in such a manor... then you wont have as many issues drawing from the host PC (ie not necessarily having to have an external power supply).
Re:x86 processors (Score:2, Interesting)
And before anyone goes to say NTFS has had those features for years , if that was really true then why can i easily delete files on any windows machine. Why is it that malware can hide in any system directory? because MSFT never enforced those standards.
In the meantime... (Score:5, Interesting)
Most of the HyperTransport updates look to be good (and, frankly, about time) but I am highly concerned that if certain manufacturers (such as Broadcom) haven't even bothered to do better than a fragmentary 1.x and have ignored 2.x entirely, there is little hope that they'll do much with 3.x.
And that's the big problem. If AMD are the only ones who ever implement the specification in full, correctly, then it doesn't offer any significant advantage. It isn't universal enough to be useful. That is the killer that has murdered so many excellent technologies. Being good - even being the best - isn't enough. If a rival is more widely adopted, then it'll be the rival that wins. The marketplace doesn't reward quality, it rewards popularity. Quality achieves nothing.
Re:Nice... (Score:3, Interesting)
Just my $0.01
Re:A port? (Score:2, Interesting)
IMHO, fiber optics- though delicate, could offer higher bandwidth. I'd rather have my whole fiber go dark from a break and know it than have one strand of many go out and not know it and have all kinds of whacky/intermittant behavior.
I still struggle to understand why fiber optics are so expensive- the lasers used are fairly cheap and the cables really aren't that complex either and are made in enough quantity.. but I guess since it's not mainstream, it's expensive.
Broadcom isn't the whole industry: (Score:3, Interesting)
Re:f*** (Score:2, Interesting)
Re:x86 processors (Score:4, Interesting)
Re:not USB (Score:3, Interesting)
Um... I hate to break this to you, but AMD-64 CPUs use Hypertransport links as their interconnect already. Which means the way you described it is exactly how it works. The 100-series Opterons have 1 HT link that goes to the system's peripheral devices and buses. The 200-series Opterons have 2 HT links: one connects it to the other CPU and the other connects to peripheral devices. I think you can guess how many links the 400- and 800-series Opterons have.
The place where this would be really interesting, though, would be the whole "one bus to rule them all" space. You could use this to cheaply add external PCI slots without the relatively expensive hardware needed to send PCI more than a couple of inches (though this can also be solved using PCIe as the interconnect). You could use this to eventually supersede low performance busses like USB.
This is how HT is used internally already. It connects the CPU to the other buses and system devices (the other end of the link is usually terminated by the southbridge ASIC. As far as clustering goes, a 1-meter link makes it somewhat doable, but rememeber that there are already high bandwidth external interconnects like Infiniband that are already in use. I didn't see anything in the article that suggested HT is capable of blowing the established technologies out of the water.
Just avoid Broadcom (Score:3, Interesting)
Instead of the harping on the implementation (which was done in a slapdash, amatuerish fashion by SiByte in order to make a quick buck - and screw the customer), you should blast Broadcom for basically dropping support for this CPU. Broadcom has done almost nothing whatsoever to improve the CPU. In fact, they go far out of their way to avoid the needed improvements. Witness the completely bogus (and nearly useless) JTAG support for the 1250.
They used to have GDB support for it for free. That's all gone; and in fact no longer works with the new Rev C 1250's. Instead, you have nearly useless third-party support from Corelis and Greenhills.
Forget source code debugging if you have a ClearCase SCM, unless you want to go through a bit of pain and hackery.
And, hells bells, let's not talk about the memory controller, which is the worst one I've ever seen. If there were ever anything which needed improvement, it is that.
In short, if you chose the BCM1250, you were an idiot and deserve what you got. No sane embedded person would do so. A clueless architect might, but not a real embedded engineer.
I once had to inherit this mess; and I'm delighted to be done with it.
So just avoid Broadcom altogether. They have an established track record of leaving you high and dry should you make the mistake of depending on them. And they just don't give a damn about their customers.
Re:So the CPU will still be waiting for RAM? (Score:3, Interesting)
And before you say that that is too little RAM.... Other CPU's in the system would have such RAM-setup as well. There could also be traditional memory-banks attached to the Nortbridge as well. So each CPU in the system would have 256-512MB of VERY fast RAM attached directly to the CPU. In addition to that, they could also access the RAM on other CPU's (like AMD64-machines do today). AND in addition to that, there would also be traditional memory-banks attached to the northbridge, for memory-expansion. The Northbridge-RAM would be shared with all the CPU's in the system (naturally).
Of course, such a system would cost a bit more than current systems do. But it would have a metric assload of bandwidth. Would such system make any sense at all? Considering that vid-card makers can sell such RAM attached to relatively large GPU for around 500 bucks, why couldn't CPU-makers sell a smaller CPU with similar RAM for about same price?