The DS15 (HyperBrick), DS25 (Granite), and ES45 (Privateer) use the Titan core logic, the successor to Tsunami. ¹⁾ The DS15 has an EV68 CPU and replaced the DS10, largely because the Tsunami chipset had reached end of life. ²⁾ The DS15 and DS25 were also sold, with graphics, as AlphaStations. ^{3) 4)}

The DS15A is a RoHS compliant DS15, otherwise identical and interchangeable. ^{5) 6) 7)}

• One 1 GHz 21264C with 2 MiB of onboard ECC cache, in a 3U enclosure
• 512 MiB, 1 GiB, or 2 GiB of SDRAM, up to 4 GiB
• Four 64-bit PCI expansion slots on a riser card, two of them capable of 66 MHz, with no support for 5 V cards ⁸⁾
• The Titan P-chip supports two PCI buses, or one PCI and one AGP bus; the built-in devices are on one PCI bus and the riser slots on the other ⁹⁾
• Onboard dual-port Ultra160 SCSI controller (Adaptec 7899) and dual 10/100BaseT Ethernet (two Intel 82559ER) ¹⁰⁾
• Internal or front access storage cage, up to 218.4 GB or 745.6 GB
• Two serial ports, COM1 doubling as the remote management console (RMC) port, PS/2 keyboard and mouse, DVD/CD-RW, 400 W power supply

• One or two 1 GHz 21264C CPUs with 8 MiB of dual data rate L2 cache each
• ECC protected memory bus and cache, 512 MiB to 16 GiB using 512 MiB, 1 GiB, 2 GiB, and 4 GiB options
• Six 64-bit PCI slots on three PCI buses: slots 1 to 4 at 66 MHz and slots 5 and 6 at 33 MHz
• Integrated dual Ultra3 SCSI adapter and dual Ethernet (10/100 and 10/100/1000)
• Six hot swap disk bays, up to 872 GB, IDE DVD-ROM/CD-R combo drive
• Two 500 W hot pluggable power supplies, with an optional third for N+1 redundancy

Except where noted, the following comes from the ES45 Technical Summary. ¹¹⁾

• One to four 21264C (EV68, 0.18 micron) CPUs at 1 GHz with 8 MiB of L2 cache at 250 MHz DDR, or at 1.25 GHz with 16 MiB at 313 MHz DDR, each with 64 KiB instruction and 64 KiB data caches on chip
• Two 256-bit memory buses at 125 MHz, 4 GB/s each and 8 GB/s in total, 120 ns latency, ECC protected. Four memory motherboards take memory options of four identical 200-pin SDRAM DIMMs, sold as 512 MiB, 1 GiB, 2 GiB, and 4 GiB options. One option gives no interleaving, two give two-way, and four give four-way. ES40 and ES45 DIMMs are not interchangeable
• Two P-chips on the PCI backplane each drive two 64-bit PCI buses, or one PCI and one 4X AGP bus on Model 1B. An Acer Labs 1543C bridges PCI 0 to ISA for the serial, parallel, keyboard, mouse, floppy, and DVD-ROM logic
• Two serial ports, a dedicated 6-pin MMJ RMC modem port, a 25-pin parallel port, PS/2 keyboard and mouse, and two SCSI breakouts
• Up to twelve 1-inch Ultra3 SCSI disks in two six-disk cages, each cage needing its own SCSI adapter, plus a DVD-ROM, a 1.44 MB floppy drive, and two half-height 5.25-inch removable media bays
• One to three 1080 W (DC) power supplies. A second is required for more than two CPUs, more than one disk cage, or more than 16 DIMMs; a third provides N+1 redundancy. Three AC cords allow three separate power sources
• A remote management console (RMC) on the system board, powered from auxiliary 5 V so that it is reachable while the system is powered off
• Sold as a tower, a pedestal with room for two additional StorageWorks shelves, and an 8U rackmount chassis

The models differ only in the PCI backplane and memory motherboards. The original Model 2 has 1 GHz CPUs and 720 W power supplies; Models 1B, 2B, and 3B were sold with 1 GHz or 1.25 GHz CPUs and take 1080 W supplies. ^{12) 13)}

The 33 MHz slots are 5 V and the 66 MHz slots are 3.3 V. Seven of the ten slots are hot pluggable on Models 2, 2B, and 3B, and four of the seven on Model 1B.

Use the final SRM version, V7.3-2, on the DS15, DS25, and ES45 (see final SRM versions). The TS202c V6.8B firmware release carries SRM V6.8-20. ¹⁴⁾

• An ES45 that stops with "Bootstrap address collision, image loading aborted" needs set heap_expand none; the console_memory_allocation old fix used on other systems does not work on the ES45 (reported under Tru64 UNIX). ¹⁵⁾
• The escape sequence from the console to the RMC on the ES45 is Esc Esc rmc. ¹⁶⁾ The DS15's RMC can halt the system, power cycle it, and report fan and temperature readings, but it has no network access. ¹⁷⁾

Current kernels support the DS15, DS25, and ES45 (CONFIG_ALPHA_TITAN, or a generic kernel), which boot from SRM with aboot. ¹⁸⁾ The kernel also recognizes the TS202c (Falcon), ¹⁹⁾ but no one has reported running Linux on it; its firmware release notes list Tru64 UNIX as its only operating system. ²⁰⁾ The SRM console on Titan machines occupies the low memory where older systems load the kernel, so the kernel must start at 8 MiB or above, and preferably 16 MiB. ²¹⁾ A generic kernel must therefore be built with CONFIG_ALPHA_LEGACY_START_ADDRESS turned off; with it on, as in the default configuration, the kernel leaves out Titan support entirely (see Kernel). ²²⁾

The DS15's onboard Intel 82559ER Ethernet ports use the e100 driver and its Adaptec 7899 SCSI controller the aic7xxx driver. ^{23) 24)}

The DS25's onboard devices are an Intel 82559ER 10/100 Ethernet controller, a Broadcom 5703C gigabit Ethernet controller, a dual-channel Adaptec AIC-7899 SCSI controller, and the Acer Labs M1543C IDE controller for the DVD-ROM. ²⁵⁾ They use the e100, tg3, aic7xxx, and pata_ali drivers. ^{26) 27)} The ES45 has no onboard network or SCSI controller; its onboard devices are the Acer Labs M1543C, whose IDE controller (pata_ali) serves the DVD-ROM, and the PCI hot-plug controllers, while network and SCSI adapters are PCI cards. ^{28) 29)}

For a serial console, see Using SRM; on the DS15, COM1 is also the RMC port (see Specifications).

Debian has run on all three supported models. An ES45 with three 1.25 GHz CPUs, "Imago", was a Debian build daemon in 2012. ³⁰⁾ A DS15 was running Debian Ports with Linux 5.8.1 in 2020. ³¹⁾ Debian's SMP kernels failed on an ES45 and a DS25 from version 5.4 on; in 2022 a self-built Linux 6.0.7 SMP kernel worked again on the dual-CPU DS25, ^{32) 33)} and the same DS25 ran Debian's own 6.3.0-1-alpha-smp kernel in 2023. ³⁴⁾

• Loose CPUs: on early ES45s the CPU mounting could work loose in use, causing random crashes; Compaq fitted retaining sleeves and later a hardware fix. ³⁵⁾
• 120 V power: some ES45 supplies are built for 200 to 240 V only: an ES45 "B" model reports every supply as failed on 120 V. ³⁶⁾
• Power: an ES45 with three 1.25 GHz CPUs and 4 GiB of memory draws about 600 W. ³⁷⁾

The DS15 was withdrawn from sale in late 2006. ³⁸⁾ The DS15A remained on sale into 2007. ³⁹⁾

The following sources conflict with each other or with the account given above. They are listed here for further investigation.

• Titan systems in the kernel configuration
  • arch/alpha/Kconfig, Linux 6.10: the ALPHA_TITAN help text says "AlphaServer ES45/DS25 SMP based on EV68 and Titan chipset."
  • "Re: Sanity checking needed of Alpha subarch codenames in d-i manual", Jay Estabrook, debian-alpha, 8 Nov 2004, includes the DS15.