What would your ideal upgrade be right now for your Amiga(s)

[Karlos]

Hmm... I'd have to say a USB card that can run at USB2 speeds for me A1200's...

Likewise I'd like the same basic thing, but ethernet. Unfortunately I think we're both stymied on that one.

Full-blown USB2 transfer rate is something like 320 Mbit/sec for bulk transfers. I'm really not sure what you could connect to your A1200 to get that sort of sustained throughput especially to/from system memory. Your best bet would be a GRexx PCI with some sort of USB2 card fitted, assuming all the necessary drivers exist.

Ideally, someone would bring out a new accelerator card with all this gear on board already. Sort of an all-round accelerator rather than just a faster CPU.

-edit-

Of course, you could argue that's exactly what the NatAmi is, albeit one that doesn't need the rest of your system.

[Karlos]

Hmmm.... despite the fact I grudgingly agree with what you say here...

I'm in cream puff right now over our other wee debacle /debate in that other thread today,

It's the internet, heated disagreements are normal behaviour (it's how you go about disagreeing that matters). I would be far more worried if everybody agreed on everything all the time...

so I'm not talking to you today, so there and na na na na na can't hear you (well I know it's really can't read you but that doesn't sound right)...

Well, you know the other problem for high speed USB is that it is very interrupt heavy. When transferring large amounts of data from one high speed USB hard drive to another on my PC, I can track the interrupt overhead by watching /proc/interrupts. Servicing said interrupts ties up the CPU, which on linux shows up as abnormal amounts "%sy" (system) CPU.

So, even assuming we had a fast enough bus to put a high speed USB2 controller on, we'd probably find that the classic amiga hardware can't service the interrupts fast enough to get it going at full speed (high speed ethernet has the same problem too, but the packets are bigger and therefore fewer are generated per unit of data transferred).

Pity firewire didn't usurp it as it was a far better hardware protocol (including DMA, for example), but that's another one of those VHS/Betamax debates.

So stop posting things that agrees with what I say or I'll end up in a bigger sulk and end up spamming the Sky News website and taking it out on those poor journos over there, I gave the poor sods an earbashing yesterday...

So leave me out of things for today as I canny be bothered and I'll just end up peed off and start ranting again about anything and everything...

Sorry :lol:

Ok, this is the last one then for today.

I'm off to take some of me meds as I've either missed them today or they don't work anymore... or perhaps it's time for a wee stay in the loony bin again...

Anywhoo, I'm going to bile ma heid and see if that helps...

PS: Me bloody useless dog hasn't died today , now I'll need to figure out what wrong with him now...

Does he do it often?

[Karlos]

You recognize that the Deneb is a High Speed USB 2.0 card available for years now that can have a throughput of over 8.5 MByte/sec on an Amiga Classic system?

Which is certainly impressive, but 8.5MB/s, whilst fast for a classic Amiga is not high speed as per USB2 standards for bulk transfers, ~30MB/s is. My reply was on the basis of achieving the latter, ie USB2 transfer rates comparable to what everybody else is used to.

And about the interrupts: well, it very much depends on the controller and the driver. The Deneb transfers double buffered chunks of 24 KB each per interrupt. That's a lot bigger than your average 1500 Byte Ethernet frames... Even the Subway/Highway does not cause an interrupt for every 64 bytes transferred...

Of course, but that's an implementation issue. There's not a lot in the standard that I'm aware of that dictates how much data a hardware device should buffer. I've seen USB2 controllers that will happily generate an interrupt every packet. Likewise, I've seen ethernet adapters that seem to implement a sensible degree of buffering and don't produce quite the same overhead - very important given the speeds they can reach.

[Karlos]

You know that most Amiga classic systems have a memory bandwidth in one direction (i.e. read OR write) of often less than 15 MB/sec?

Absolutely, which is why I said in my first post about it that actually finding something inside the amiga to connect it to that could handle full USB2 bulk transfer speeds would be a problem (the interrupt load comment came after that). I actually suggested that something like a USB2 card attached by GRexx might be a viable option *if* a sensible stack and driver set existed.

Let alone a transfer between TWO ports (i.e. read AND write). Did you ever benchmark the USB bulk performance of real USB devices? Then you would know that the theoretical 30 MB/sec raw bandwidth of the USB spec are not reached in practice. Even on a Pegasos or MacMini, I never got much faster than around 23 MB/sec.

Actually, I have several high speed external USB2 drives. The highest USB2 bulk transfer I've achieved copying data from one to another on my PC is around 28MB/s when copying files of around 1GB in size. I've never seen it go higher than that, but as I said, it does put a measurable load on the system in terms of interrupt handling. Fortunately, being a quad core system, that still leaves plenty of CPU for other tasks.