Here is my review of the new Zulu Wide-SCA. The Zulu Wide-SCA is a 16-bit Ultra Wide SCSI emulator, enables read speeds of up to 33 megabytes/second with the Raspberry Pi RP2350B microcontroller. ZuluSCSI supports Ultra Wide synchronous SCSI transfers, with read speeds up to 33 megabytes/second, and write throughput of up to 18 megabytes/second. This in my opinion is a significant achievement in SCSI emulation, something the SGI community has been wanting for quite some time. An 80-pin Wide/Ultra Wide SCSI controller is required to achieve maximum throughput, along with a sufficiently-fast SD card.
I will be testing the Zulu Wide-SCA in my SGI o2 which is equipped with a 300mhz R5000 processor. I will for comparisons sake, include a benchmark vs a Fujitsu 10K RPM spinning SCA SCSI disk. It is worth pointing out that this review assumes a basic understanding of ZuluSCSI and it's operation, as this is an evolution of the ZuluSCSI product line. If you are not aware of the advantages and usability of ZuluSCSI please click here.
Firstly the device itself:
The PCB comes in a beautiful red with gold flashing, the layout and design of the circuit is extremely clean and efficient, hat's off to the designer. I particularly like the small touches, ie; having a spring-eject-mechanism on the SD card, and using USB-C rather than micro which adds to the professional presentation of the product overall. The second photograph shows the Zulu Wide-SCA in the o2 caddy ready to be installed inside the machine. The 3D printed bracket specifically designed for the unit was highly appreciated and worked perfectly.
Benchmarks
SD Card used: Official Raspberry Pi 256GB Class 10 SD card
Here we can see the excellent performance offered by the ZuluSCSI Wide-SCA. We can see that it truly shines in random write/read benchmarks vs the traditional disk, just comparing the smaller byte-sizes the Zulu completely destroys the Fujitsu disk by over 200% in raw performance figures. The traditional disk manages to claw itself back in sequential transfers and in larger byte-size transfers, but when 'using' your SGI on an every-day basis, the smaller byte-transfer speeds make the biggest difference in OS responsiveness. Even at the large-byte transfers we see the ZuluSCSI Wide-SCA match the spinning disk, saturating the SCSI bus at approximately 33mb/s for reads. The only area where the Zulu performs less than the spinning disk is in the writes, which are still at a respectable speed at approximately 20mb/s. It is important to remember that these performance figures are heavily dependant on the quality of the SD card! Not only the quality, but also how the SD card is prepared. More on this in the next section.
Importance of SD card authenticity and preparation
Using this ZuluSCSI Wide-SCA has actually brought something to my attention - the prevalence of FAKE SD cards on the market. I previously used Sandisk 300mb/s and 200mb/s SD cards in other SCSI emulators and did not think twice, but when trying my cards in the ZuluSCSI Wide-SCA it became apparent that there was a serious problem - the speeds I achieved in benchmarks were highly compromised! At first I was confused, until I started to uncover the fact that my SD cards were FAKE. I had purchased them on Amazon and previously had no idea, they seemed genuine to me. I do not want to clutter this benchmark thread with images unrelated to the real performance achieved by using authentic cards, but I will leave a 'FakeSD.png' in the attached images of this thread, so you can see the difference in performance. Overall: The ZuluSCSI Wide-SCA will expose any fake SD cards you may have, it demands the highest quality SD cards without compromise!
In terms of preparation I am talking about formatting the SD card using the official SD-card formatter by the SD Association. When I first heard of this I initially rolled my eyes thinking it would have no effect, but time-after-time it has been shown that doing a full format with --overwrite will significantly improve the performance of the SD card when used in high-speed devices like the ZuluSCSI Wide-SCA. Make sure to properly prepare your card, use the --overwrite option.
Where to buy
Official price on Rabbit Hole Computing website as of Dec 2025: $129
My recommendation: I can highly recommend the ZuluSCSI Wide-SCA. It is the perfect upgrade from using vintage spinning disks. Not only does it provide the levels of speed we require on our platform, but it also provides the excellent usability that comes with a ZuluSCSI product ie; easy management of disk images, making system backups a breeze. This also includes the ability to mount CD-ROM images which is extremely useful.
I will be testing the Zulu Wide-SCA in my SGI o2 which is equipped with a 300mhz R5000 processor. I will for comparisons sake, include a benchmark vs a Fujitsu 10K RPM spinning SCA SCSI disk. It is worth pointing out that this review assumes a basic understanding of ZuluSCSI and it's operation, as this is an evolution of the ZuluSCSI product line. If you are not aware of the advantages and usability of ZuluSCSI please click here.
Firstly the device itself:
The PCB comes in a beautiful red with gold flashing, the layout and design of the circuit is extremely clean and efficient, hat's off to the designer. I particularly like the small touches, ie; having a spring-eject-mechanism on the SD card, and using USB-C rather than micro which adds to the professional presentation of the product overall. The second photograph shows the Zulu Wide-SCA in the o2 caddy ready to be installed inside the machine. The 3D printed bracket specifically designed for the unit was highly appreciated and worked perfectly.
Benchmarks
SD Card used: Official Raspberry Pi 256GB Class 10 SD card
| ZuluSCSI Wide-SCA | Fujitsu 10K RPM 300GB Disk |
 |  |
Here we can see the excellent performance offered by the ZuluSCSI Wide-SCA. We can see that it truly shines in random write/read benchmarks vs the traditional disk, just comparing the smaller byte-sizes the Zulu completely destroys the Fujitsu disk by over 200% in raw performance figures. The traditional disk manages to claw itself back in sequential transfers and in larger byte-size transfers, but when 'using' your SGI on an every-day basis, the smaller byte-transfer speeds make the biggest difference in OS responsiveness. Even at the large-byte transfers we see the ZuluSCSI Wide-SCA match the spinning disk, saturating the SCSI bus at approximately 33mb/s for reads. The only area where the Zulu performs less than the spinning disk is in the writes, which are still at a respectable speed at approximately 20mb/s. It is important to remember that these performance figures are heavily dependant on the quality of the SD card! Not only the quality, but also how the SD card is prepared. More on this in the next section.
Importance of SD card authenticity and preparation
Using this ZuluSCSI Wide-SCA has actually brought something to my attention - the prevalence of FAKE SD cards on the market. I previously used Sandisk 300mb/s and 200mb/s SD cards in other SCSI emulators and did not think twice, but when trying my cards in the ZuluSCSI Wide-SCA it became apparent that there was a serious problem - the speeds I achieved in benchmarks were highly compromised! At first I was confused, until I started to uncover the fact that my SD cards were FAKE. I had purchased them on Amazon and previously had no idea, they seemed genuine to me. I do not want to clutter this benchmark thread with images unrelated to the real performance achieved by using authentic cards, but I will leave a 'FakeSD.png' in the attached images of this thread, so you can see the difference in performance. Overall: The ZuluSCSI Wide-SCA will expose any fake SD cards you may have, it demands the highest quality SD cards without compromise!
In terms of preparation I am talking about formatting the SD card using the official SD-card formatter by the SD Association. When I first heard of this I initially rolled my eyes thinking it would have no effect, but time-after-time it has been shown that doing a full format with --overwrite will significantly improve the performance of the SD card when used in high-speed devices like the ZuluSCSI Wide-SCA. Make sure to properly prepare your card, use the --overwrite option.
Where to buy
Official price on Rabbit Hole Computing website as of Dec 2025: $129
ZuluSCSI - A hardware SCSI HDD & CD-ROM emulator
##### Where to Buy ZuluSCSI #### United States * [Rabbit Hole Computing (Northern California)](https://shop.rabbitholecomputing.com/collections/zuluscsi) - Direct from the source * [SamplerZone.com (Tennessee)](https://samplerzone.com/collections/zuluscsi) - Specializes in Musical Samplers *...
zuluscsi.com
My recommendation: I can highly recommend the ZuluSCSI Wide-SCA. It is the perfect upgrade from using vintage spinning disks. Not only does it provide the levels of speed we require on our platform, but it also provides the excellent usability that comes with a ZuluSCSI product ie; easy management of disk images, making system backups a breeze. This also includes the ability to mount CD-ROM images which is extremely useful.
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