Written by Christopher on Monday, March 29, 2021.
Are you looking for a Firewire to USB adapter or vice-versa? Do you need to hook your old external hard drive or DV camera to your PC or MAC to get some old files or video back?
In todays article, I will explain why Firewire to USB does not exist and never will.
On computers, Firewire and USB work quite differently. USB was first introduced in roughly 1995 and was famously showcased by Bill Gates when it crashed a Windows PC at a tech expo. USB has safety and security layers to it that make it a LOT more secure than Firewire. It does increase the latencey and slows the bandwidth a bit too. But this isn't an issue in modern USB. Most computers have a PCI bus. This bus can directly address memory and interupts on the system. Which can me a massive securtiy hole. To prevent this and make USB more hot-plugable, an OHCI/UHCI layer exists between the USB root hub and the PCI Bus. This means that no USB device can directly access the computers internal memory spaces or the interupts of the system.
Firewire however, can directly access the memory of the system. Not only does Firewire operate on different voltages than USB, but since it can also address memory directly on a PC/MAC it makes it completely incompatable with the USB interface and protocols. This shows that there is no manner of adapter that you can make, that would allow it to work. No adapter you construct would allow the USB root hub to access the PCI bus like Firewire can. You can consider this a limitation of USB.
"But I see Firewire to USB adapters on amazon, and some of them have good reviews!"
There is two things going on there:
1 - Most if not all the reviews are fake.
2 - There are a SMALL number of digital cameras that use a Firewire port, but don't actually use Firewire at all. They just used the port, and wired it up for USB. So the camera never supported Firewire in the first place. These rare cases are where sporatic "good" reviews come from.
Don't be fooled. If you have a Firewire hard drive or camera, those Amazon adapters WON'T work for you. Save your money.
"How can I use these old Firewire devices then?"
There are a few options:
1 - Add a PCI Firewire card to your PC or MAC if you can.
2 - Buy an old PC or MAC that has native Firewire on it.
3 - Buy an old Macbook or laptop that already has a Firewire port on it.
4 - If its an external hard drive, then just remove the hard drive from the enclosure and either add it internally to your computer, or get a USB to IDE/SATA adapter from us.