PC hardware acronyms and code words

Last modified: Fri Sep 27 19:01:08 EDT 2013

Since this glossary began as an attempt to sort out the obfuscatory nomenclature of Core-whatever-whatever processors, I still haven't gone back and filled in all of the older stuff.  You didn't need a code book to figure out that a K6 was better than a K5, a Pentium 4 was better than a Pentium III, etc.

TermWikipediaLocal definition
1394IEEE 1394 interfaceSee IEEE 1394.
ACPIAdvanced Configuration and Power InterfaceAdvanced Configuration & Power Interface.  Incorporates APM.
AGPAGP(Accelerated Graphics Port)  Video card interface in common use from 1998 (preceded by PCI) to 2004 (succeeded by PCI-E).  4x = 1 GB/s; 8x = 2 GB/s.
AGP ProAGPOddball interface, avoid.
AHCIAdvanced Host Controller Interface(Advanced Host Controller Interface)  A SATA enhancement.  It is reported that enabling AHCI in BIOS setup without first installing special drivers for Windows XP will kill the installation.  C.f. APIC.
AMD64x86-64CPU feature that allows "real" 64-bit addressing.  Unlike the "fake" 64-bit addressing of PAE, the memory space of a given process is not limited to 4 GiB.
APFC(Power supply feature)  Active Power Factor Correction, a feature that reduces electrical load and interference with other devices in your house but does nothing to reduce your electric bill.
APICIntel APIC ArchitectureAdvanced Programmable Interrupt Controller.  Local APIC (LAPIC) is a good thing to enable in BIOS setup, but enabling it after Windows XP has been installed can kill the installation.  C.f. AHCI.
APM(Advanced Power Management)  Power management interface that became available in early ATX PCs when the power button became fly-by-wire.  Supports ready, stand-by, suspended, hibernation, off.  Although ACPI appeared on the scene shortly after APM, its early implementations were buggy, so it remained necessary to use plain APM until 2000 or so.  Older ATX PCs that lack a working ACPI interface can usually be powered down using plain APM.
A-series APUAMD FusionAMD "Accelerated Processing Unit" with integrated graphics, 2011–current.  This is for midrange only; the performance segment is served by FX-series CPUs.
AT(1) An obsolete form factor, not compatible with ATX.  (2) The old IBM architecture that is ancestor to all modern PCs.  (PC begat XT, and XT begat AT, and AT begat everybody.)
ATAAT Attachment(AT Attachment)  See IDE and SATA.
ATAPIAT Attachment(AT Attachment Packet Interface)  See IDE.
Athlon 64Athlon 64AMD single-core desktop processor, 2003–2005 (succeeded by Athlon 64 X2).
Athlon 64 EE/SSAthlon 64 that functions at lower voltage.
Athlon 64 FXAthlon 64 FXF-ing X-pensive gaming version of Athlon 64 or Athlon 64 X2.
Athlon [64] X2 [BE]Athlon 64 X2AMD dual-core desktop processor, 2005–2007 (succeeded by Phenom X4).  The 64 nomenclature is sometimes omitted as being redundant.  BE = "Black Edition" with unlocked multiplier.
Athlon 64 X2 EEAthlon 64 X2 that functions at lower voltage.
Athlon IIAthlon IIAMD "budget" processor, 2009–current.
Athlon NeoAthlon NeoAMD low-power, low-profile notebook processor, 2009–current.
Athlon XPAthlon XPAMD desktop processor, 2001–2003 (succeeded by Athlon 64).
AtomAtomFamily of Intel low-power processors usually appearing in netbooks, 2008–current.
ATXATX(1) The standard tower case type / form factor.  Cases are generically described as full tower, mid tower and mini tower, but this tells you nothing except general size.  The benchmark is motherboard compatibility, which will be ATX (sometimes with measurements), Mini-ATX, MicroATX, or Flex ATX.  (2) A PSU standard.
Baby ATAn obsolete form factor that is not quite the same as mini-AT.
BTXBTX (form factor)Failed replacement for ATX promoted by Intel 2005–2006.
CCFLCold Cathode Fluorescent Lamp.
CeleronCeleronIntel "budget" processor, 1998–current.
COA(Microsoft)  Certificate of Authenticity / Authority, the dinky paper thing with the license key that allows you to install Microsoft software.
Core 2 DuoIntel Core 2Intel dual-core processor, available in both desktop (Socket T) and laptop (Socket M / Socket P) applications, 2006–2008 (succeeded by Core 2 Quad).
Core 2 ExtremeIntel Core 2Extra-expensive gaming version of Core 2 Duo or Core 2 Quad.
Core 2 Extreme QuadIntel Core 2Extra-expensive gaming version of Core 2 Quad.
Core 2 QuadIntel Core 2Intel 4-core processor, available in both desktop (Socket T) and laptop (Socket P) applications, 2007–2008.  Succeeded by Core i7.
Core 2 SoloIntel Core 2Intel single-core laptop processor, 2007–2008.  Oddball, essentially a budget processor, released after the Core 2 Duo.
Core DuoIntel CoreIntel dual-core laptop processor, 2006–2008 (succeeded by Core 2 Duo).
Core i3Intel Core i3Obfuscatory new Intel branding for processors not quite as good as i5, 2010–current.
Core i5Intel Core i5Obfuscatory new Intel branding for dual- and quad-core processors not quite as good as i7, 2009–current.
Core i7Intel Core i7Obfuscatory new Intel branding for quad-core processors available in both desktop and laptop applications, as well as some dual-core laptop processors, 2008–current.  Mobile processors are indicated by an M suffix, e.g., Core i7-920XM.
Core i7 Extreme EditionIntel Core i7Extra-expensive version of Core i7, now with 6 cores (2011).
Core SoloIntel CoreCore Duo, one core no workee.
CPUCentral Processing Unit (duh).  See also GPU.
CrossFireATI CrossFireATI's response to nVidia's SLI.  All three of the gamers who went with ATI over nVidia now buy two graphics cards each.
DDRDDR SDRAM(Double Data Rate)  184-pin SDRAM memory type used 2002–2004, commonly known by names ranging from DDR-200 / PC-1600 through DDR-500 / PC-4000.
DDR2DDR2 SDRAM(Double Data Rate 2)  240-pin SDRAM memory type used 2004–2008, commonly known by names ranging from DDR2-400 / PC2-3200 through DDR2-1200 / PC2-9600.
DDR3DDR3 SDRAM(Double Data Rate 3)  240-pin SDRAM memory type used 2008–current, commonly known by names ranging from DDR3-800 / PC3-6400 through DDR3-2000 / PC3-16000.
DIMMDIMMDual In-line Memory Module.  168-pin SDR, 184-pin DDR, 240-pin DDR2, and 240-pin DDR3 SDRAM memories are all DIMMs.  See also SIMM.
DSPDelivery Service Partner, a term once used by Microsoft to mean OEM system builder.
D-SubD-subminiatureGeneric term for a generic connector type misused to refer specifically to the standard old analog VGA connector.
DuronDuronAMD "budget" processor, 2000–2004 (succeeded by Sempron).
DVD-R/RWBurnable DVD formats blessed by the DVD Forum (formerly known as the DVD Consortium).  See DVD+R/RW for comparison.
DVD+R/RWBurnable DVD formats blessed by the DVD+RW Alliance.  The fact that DVD+R/RW disk capacities are well-specified instead of just "at least 4.7 GB" is a minor technical advantage versus DVD-R/RW.  Also, Dell has been known to ship optical drives that are crippled in firmware so that they will only burn DVD+R/RW.  Otherwise, DVD+R/RW and DVD-R/RW are equivalent in all practical respects.
DVD+R9Same as DVD+R dual layer.
DVIDigital Visual Interface(Digital Visual Interface)  The plug that replaced the standard old analog VGA connector.
EAXEnvironmental audio extensions(Environmental Audio Extensions)  A foo-foo sound card feature that might work in a few video games.
EIDEAT AttachmentOne of the incarnations of IDE.
EISAExtended Industry Standard ArchitectureExtended ISA, a 32-bit extension of ISA that is backward-compatible to ISA.  See ISA.
EM64Tx86-64Extended Memory 64-bit Technology, one of Intel's previous names for what they now call Intel 64.
EPPEnhanced Performance Profiles(Extended/Enhanced Performance Profile)  nVidia's version of XMP, an extension of SPD for overclocking.
eSATAExternal SATA(External SATA)  (1) A quixotic attempt by SATA to compete with USB and IEEE 1394, seemingly forgetful that only a fraction of the deployed base of SATA controllers supported hotplug.  (2) A successful attempt by SATA to seize market share in the vacuum left by the non-committal rollout of USB 3.0, now that the entire deployed base of SATA controllers supports hotplug.
ExpressCardExpressCardLaptop expansion card interface, 2004–current.  Succeeds PC Card / CardBus.
FCPGA6Socket MSame as Socket M.
FireWireIEEE 1394 interfaceApple proprietary name for IEEE 1394.
Flex ATXA shrunken ATX form factor.  See also Mini-ATX, MicroATX.
FX-series CPUList of AMD FX microprocessorsAMD 4 to 8-core desktop processor, 2011–current.  Not the same as Athlon 64 FX.
GPUGraphics Processing Unit, a chip installed on modern graphics cards to make them cost more.
Hardware RAIDHardware-basedRAID such that all mapping is done by a dedicated controller and there is no need for any special drivers or operating system configuration.  As far as the operating system knows, it's just a hard drive.  Preferable to Software RAID.
HDD(Hard Disk Drive)  Hard drive.
HDRHigh dynamic range rendering(High Dynamic Range)  (1) A foo-foo GPU feature that might work in a few video games.  (2) A research-stage LCD monitor technology for increasing contrast.
HT(1) HyperTransport.  (2) Hyperthreading.  (3) Home Theater.
HTPCHome Theater PC.
HyperthreadingFeature of some Intel CPUs that allows a single core to represent itself to the operating system as two cores and juggle two concurrent threads to achieve higher CPU utilization.  It was available during the Pentium 4 era, disappeared as multicore CPUs became the norm, and came back in the Core i7.
IDEAT Attachment(Integrated Drive Electronics)  Original and most commonly used name for the hard drive interface used from the dawn of time until 2008.  Maxes out at 133 MHz.  Notable for clunky, wide ribbon cables and master/slave cable sharing, it was expanded to work with optical drives and other removal media drives under the name ATAPI.  Hard drives switched from IDE to SATA in 2004, but a mysterious unavailability of SATA optical drives forced IDE to limp along until 2008.  See also Ultra DMA.
IEEE 1394IEEE 1394 interfaceA peripheral connection standard that competed poorly with USB and is dying a slow death.
IGP(Integrated Graphics Processor)  Processor for graphics support integrated with mobo chipset.
Intel 64x86-64Intel's current name for their implementation of AMD64.
ISAIndustry Standard ArchitectureThe old AT bus used 1981–2000 (succeeded by VLB and PCI).  Although limited in bandwidth, the ISA bus enabled sound cards, modems and such to work equally well in DOS, Windows, or Linux without vendor- and OS-specific drivers.
ItaniumItaniumAn Intel server processor that is not x86, hence not applicable for a home PC.  See also, Xeon.
JBOD(Just a Bunch of Disks) Also known as linear RAID; multiple volumes are concatenated to make one large volume with no striping or mirroring.  Unlike RAID 0, the volumes can be different sizes.
KVMKeyboard, Video & Mouse.
LGA 775LGA775Same as Socket T.
LGA 1150LGA 1150Intel desktop CPU interface used by Core i5 and Core i7 (2013–current).
LGA 1155LGA 1155Intel desktop CPU interface used by Core i5 and Core i7, 2011–2013 (superseded by LGA 1150).
LGA 1156LGA 1156Intel desktop CPU interface used by Core i5 and Core i7, 2009–2011 (superseded by LGA 1155).
LGA 1366Socket BSame as Socket B.
LGA 2011LGA 2011Intel desktop CPU interface used by Core i7 Extreme Edition (2011–current).
Matrix RAIDIntel Matrix RAIDHybrid of RAID 0 and RAID 1; some stuff striped, other stuff mirrored.
MCP(Media and Communications Processor)  What nVidia calls the southbridge in their nForce chipset.  C.f. SPP.
MicroATX / µATXA shrunken ATX form factor that is not quite the same as Mini-ATX.
Mini-ATXA shrunken ATX form factor that is not quite the same as MicroATXMobos are no longer available in this form factor.
mini-ATAn obsolete form factor that is not quite the same as Baby AT.
mini-ITXMini-ITXSmallest form factor for which you can buy case and mobo separately.  Mobo is 17 cm × 17 cm.  See also nano-ITX, pico-ITX, mobile-ITX.
mobo(like mofo) Motherboard.
mobile-ITXMobile-ITXSmallest of the small form factors.  Mobo is 6 cm × 6 cm.
mPGA478Socket 478Same as Socket 478.
NanoVIA NanoLow-power processor from VIA, 2008–current.  Competes with Atom.
nano-ITXNano-ITX12 cm × 12 cm mobo form factor, sized between mini-ITX and pico-ITX.
OEMOriginal Equipment Manufacturer.  Narrowly interpreted, OEM versions of software or hardware are only available to large retailers like Dell; however, software versions intended for use by independent "system builders" are usually also described as OEM software.  Microsoft licensing requires retailers to sell OEM versions of Microsoft products only in conjunction with hardware components that are essential to building a new system.  OEM versions of Windows are a fraction of the price of retail versions, but Windows Activation permanently locks them to a specific hardware configuration so that the software can never be moved to another PC, nor even used on the same PC after a significant hardware change.  Older versions such as Windows 98 did not have this "feature."
OpteronOpteronAMD server processor, 2003–current.
PAEPhysical Address Extension(Physical Address Extension)  CPU feature that allows addressing of up to 64 GiB of memory on a 32-bit architecture.  The memory space of a given process still cannot exceed 4 GiB.  This feature has been available in Intel processors since the Pentium Pro (circa 1996) and is now required for certain Linux memory optimizations to work.
PATPage attribute table(1) A memory management feature of Pentium III and newer.  (2) (Parallel Address Translation)  A minor optimization of memory access speed.
PATAAT AttachmentParallel ATA, the underlying spec of IDE / EIDE.
PCIPCI Local Bus(Peripheral Component Interconnect)  64-bit parallel bus used 1994–current (succeeded by PCIe).  Comes in 33 MHz and 66 MHz flavors.  The replacement of ISA by PCI ended the era of interoperable add-in cards:  sound cards, modems and such became completely dependent on vendor- and OS-specific drivers, breaking compatibility with any operating systems not supported as well as forward compatibility to OS versions appearing after the end of support.  C.f. Windows lock-in, planned obsolescence, brick, connector conspiracy, abandonware, DMCA, cloud computing.
PCI-E / PCIePCI ExpressPCI-Express, successor to AGP and PCI, used 2004–current.  PCI-E 16x (16 slot) = 4 GB/s.
PCIe 2.0PCI ExpressBackward-compatible doubling of PCI-E bandwidth.
PCIe 3.0PCI ExpressBackward-compatible doubling of PCI-E 2.0 bandwidth; available since late 2011.
PCI-XPCI-X64-bit PCI run at 133 MHz; used only in servers.
PEGPCI-Express Graphics.
Pentium DPentium DIntel dual-core desktop processor without Hyperthreading, 2005–2006 (succeeded by Core 2 Duo).
Pentium Dual-CorePentium Dual-CoreMisleadingly named Core 2-based processor with less cache.  2007–2008.
Pentium EEPentium D[Extremely Expensive] gaming version of Pentium D with Hyperthreading.
Pentium MPentium MIntel laptop processor, 2003–2006 (succeeded by Core Duo).
Pentium 4Pentium 4Intel single-core desktop processor, 2000–2006 (succeeded by Core 2 Duo).
Pentium 4 EEPentium 4[Extremely Expensive] gaming version of Pentium 4.
PFC(Power supply feature)  Power Factor Correction, see APFC.
Phenom II X2 [BE]Phenom IIPhenom II X4, two cores no workee.  BE = "Black Edition" with unlocked multiplier.
Phenom II X3 [BE]Phenom IIPhenom II X4, one core no workee.  BE = "Black Edition" with unlocked multiplier.
Phenom II X4 [BE]Phenom IIAMD quad-core desktop processor, 2009–2012 (succeeded by FX-series CPU).  BE = "Black Edition" with unlocked multiplier.
Phenom II X6 [BE]Phenom IIAMD 6-core desktop processor, 2010–2012 (succeeded by FX-series CPU).  BE = "Black Edition" with unlocked multiplier.
Phenom X3 [BE]PhenomPhenom X4, one core no workee.  BE = "Black Edition" with unlocked multiplier.
Phenom X4 [BE]PhenomAMD quad-core desktop processor, 2007–2009 (succeeded by Phenom II X4).  BE = "Black Edition" with unlocked multiplier.
pico-ITXPico-ITXSecond smallest of the small form factors.  Mobo is 100 mm × 72 mm.  A complete pico-ITX system can fit into a 5¼″ drive bay.
PIOProgrammed input/output(Programmed I/O)  A CPU-intensive mode of data transfer used by the earliest IDE controllers and as a fallback of last resort by later ones.
PSUPower Supply Unit.
PWMPulse-width modulation, a way of controlling fan speed.
RAIDRAIDRedundant Array of Independent or Inexpensive Disks.  Comes in Hardware RAID and Software RAID flavors.  See RAID 0, RAID 1, RAID 0+1, RAID 5, RAID 10, Matrix RAID, and JBOD regarding the different ways of combining volumes.
RAID 0RAIDStriping for performance.  The volumes have to be the same size.
RAID 0+1RAID 0+1Mirroring (RAID 1) of striped volumes (RAID 0).
RAID 1RAIDMirroring for redundancy.
RAID 1+0RAID 1+0Striping (RAID 0) of mirrored volumes (RAID 1).
RAID 5RAIDStriping plus parity for some fault tolerance.
RAID 10RAID 1+0Same as RAID 1+0.
RAID 0/1/0+1/5/10 Matrix/JBODIndicates support for lots of different RAID types.  See RAID 0, RAID 1, RAID 0+1, RAID 5, RAID 10, Matrix RAID, JBOD.
RoHSRestriction of Hazardous Substances Directive(Restriction of Hazardous Substances)  An EU environmental directive that is causing a lot of heartburn in manufacturers of PC components.
rPGA 998ASocket G1Same as Socket G1.
rPGA 998BSocket G2Same as Socket G2.
SATASerial ATA(Serial ATA)  Hard drive (et al.) interface that succeeded IDE and remains current as of 2008.
SATA/150 or SATA-150Serial ATASee SATA 1.5 Gb/s.
SATA/300 or SATA-300Serial ATASee SATA 3.0 Gb/s.
SATA 1.5 Gb/sSerial ATAFirst generation SATA, 1.5 GHz yielding transfer rate of 150 MB/s.
SATA 3.0 Gb/sSerial ATASecond generation SATA, 3.0 GHz yielding transfer rate of 300 MB/s.
SATA 6.0 Gb/sSerial ATAThird generation SATA, 6.0 GHz yielding transfer rate of 600 MB/s.
SATA IISerial ATADeprecated misnomer for SATA 3.0 Gb/s.
SDRSDRAM(Single Data Rate)  168-pin SDRAM memory type used 1996–2002, commonly known by the names PC 100 and PC 133.
SDRAMSDRAMSynchronous Dynamic Random Access Memory.  See SDR, DDR, DDR2, DDR3.
SECCSECC (disambiguation page)(1) (Cases)  Material that is otherwise known as steel.  (2) (Single Edge Contact Cartridge)  The cartridge used for Slot 1 Pentium II and III CPUs.
SempronSempronAMD "budget" processor, 2004–2011 (succeeded by Athlon II).
SIMMSIMM(Single In-line Memory Module)  30- and 72-pin memory types used in pre-SDRAM PCs.  See also DIMM.
SLIScalable Link Interface(Scalable Link Interface)  nVidia marketing innovation that causes gamers to buy twice as many graphics cards as before.  The ATI version is called CrossFire.
Slot ASlot AAMD desktop CPU interface used by Athlon, 1999–2000 (succeeded by Socket A).
Slot 1Slot 1Intel desktop CPU interface used by Pentium II, Pentium III, and VIA C3, 1997–1999 (succeeded by Socket 370).
Socket ASocket AAMD desktop CPU interface used by Athlon and Athlon XP, 2000–2003 (succeeded by Socket 754).
Socket AM2Socket AM2AMD desktop CPU interface, 2006–2007 (succeeded by Socket AM2+).
Socket AM2+Socket AM2+Incrementally improved AMD desktop CPU interface that is theoretically backward-compatible with Socket AM2 in both directions.  An AM2+ CPU in an AM2+ mobo runs HyperTransport at 2 GHz instead of only 1 GHz.  2007–2009 (succeeded by Socket AM3).
Socket AM3Socket AM3AMD desktop CPU interface, 2009–2011 (succeeded by Socket AM3+).  An AM3 CPU can theoretically work on an AM2+ mobo but not the reverse.
Socket AM3+Socket AM3+AMD desktop CPU interface for FX-series CPUs, 2011–current.
Socket BSocket BIntel desktop CPU interface used by Core i7, 2008–2011 (succeeded by LGA 2011).
Socket FSocket FAMD server / enthusiast CPU interface, 2006–2010.
Socket FM1Socket FM1AMD CPU interface for A-series APUs, 2011–2012 (succeeded by Socket FM2).
Socket FM2Socket FM2AMD CPU interface for A-series APUs, 2012–current.
Socket G1Socket G1Intel laptop CPU interface, 2009–2011 (succeeded by Socket G2).
Socket G2Socket G2Intel laptop CPU interface, 2011–current.
Socket HLGA 1156Same as LGA 1156.
Socket H2LGA 1155Same as LGA 1155.
Socket H3LGA 1150Same as LGA 1150.
Socket MSocket MIntel laptop CPU interface, 2006–2007 (succeeded by Socket P).
Socket PSocket PIntel laptop CPU interface, 2007–2009 (succeeded by Socket G1).
Socket RLGA 2011Same as LGA 2011.
Socket S1Socket S1AMD laptop CPU interface, 2006–2010.  There were four revisions, dubbed S1g1 through S1g4; newer processors need the newer revs.
Socket TLGA775Intel desktop CPU interface, 2004–2008 (succeeded by Socket B).
Socket 5Socket 5Desktop CPU interface used by Pentium and K5, 1994–1996 (succeeded by Socket 7).
Socket 7Socket 7Desktop CPU interface used by Pentium, K5, and K6, 1996–1998 (succeeded by Super Socket 7 for AMD and Slot 1 for Intel).
Socket 370Socket 370Intel desktop CPU interface used by Pentium III and VIA C3, 1999–2000 (succeeded by Socket 423).
Socket 423Socket 423Intel desktop CPU interface used by Pentium 4, 2000–2001 (succeeded by Socket 478).
Socket 462Socket ASame as Socket A.
Socket 478Socket 478Intel desktop CPU interface used by Pentium 4, 2001–2004 (succeeded by Socket T).
Socket 479Socket 479Pentium M-specific socket.  Note:  Socket M also has 479 pins and has been referred to as Socket 479, but the two are not compatible.
Socket 604Socket 604Xeon-specific socket.
Socket 754Socket 754AMD CPU interface, 2003–2004 (succeeded by Socket 939).
Socket 775LGA775Same as Socket T.
Socket 939Socket 939AMD CPU interface, 2004–2006 (succeeded by Socket AM2 and Socket S1).
Socket 940Socket 940AMD server socket that requires registered memory.
Socket 1207Socket FSame as Socket F.
Software RAIDOperating system based ("software RAID")RAID that only works if you install a driver or configure the operating system to do the work.  The RAID that comes with the mobo is always software RAID.  (N.B., as of 2006-07, Wikipedia reserves the term "software RAID" for RAID that is implemented entirely in the operating system, while the approach used in mobos, where there is BIOS support and a driver, is called firmware/driver-based RAID or "fakeraid."  I have not seen the term fakeraid used in the wild; both cases are simply called software RAID.)
SPDSerial Presence Detect(Serial Presence Detect)  A way for memory modules to inform the mobo chipset of what timings they support.
SPP(System Platform Processor)  What nVidia calls the northbridge in their nForce chipset.  C.f. MCP.
SPP 100An external parallel port of some sort.
SSDSolid-state drive(Solid State Disk/Drive)  Flash memory with an IDE or SATA interface so as to replace an HDD.  Currently these are crazy-expensive and only available in laptop form factors.  C.f. "horseless carriage" (it's not a "disk drive" in any sense, it just fulfills the same function).
Super Socket 7Super Socket 7Desktop CPU interface used by K6-2 and K6-III, 1998–2000 (succeeded by Slot A).  Super Socket 7 is frequently just called Socket 7.
Turion 64Turion 64AMD single-core laptop processor, 2005–2006 (succeeded by Turion 64 X2).
Turion [64] X2Turion 64 X2AMD dual-core laptop processor, 2006–2009 (succeeded by Turion II).  The 64 nomenclature is sometimes omitted as being redundant.
Turion 64 X2 UltraTurion 64 X2 UltraAMD dual-core laptop processor, 2008–2009? (succeeded by Turion II Ultra?)
Turion IITurion IIAMD dual-core laptop processor, 2009–current.
Turion II UltraTurion II UltraExtra-expensive version of Turion II.
Ultra/ATA XXAT AttachmentPopular way of specifying Ultra DMA bandwidth (XX MHz) instead of mode number.  See Ultra DMA.
Ultra DMAAT AttachmentFast PATA mode.  Ultra DMA mode 2 = Ultra/ATA 33; Ultra DMA mode 4 = Ultra/ATA 66; Ultra DMA mode 5 = Ultra/ATA 100.
USBUniversal Serial Bus(Universal Serial Bus)  The peripheral connection standard that succeeded 9-pin serial and 25-pin parallel ports.  Interoperability of USB devices is generally good but not as reliable as the old standards.
VFDVacuum fluorescent display(Vacuum Fluorescent Display)  The sort of display that produces the bright numbers on the front of VCRs, DVD players, microwave ovens, etc.; now available on HTPC cases.
VGAVideo Graphics Array(Video Graphics Array)  Base standard to which all modern graphics cards conform.  (CGA begat EGA, and EGA begat VGA, and VGA begat everybody.)  VGA brought us the D-Sub connector that reigned uncontested until the introduction of DVI.
VL / VLBVESA Local BusVESA Local Bus, a short-lived successor to ISA that was backward-compatible to ISA cards.  Succeeded by PCI.
VRMVoltage regulator module(Voltage Regulator Module)  Yet another mobo component that suddenly needs a heat sink to avoid bursting into flames.
VSB(PSU ratings)  Volts StandBy, which is similar to flea power.  A specification reading +5VSB@2A means that 2 amps will be available on some +5 volt connector even when the PSU is "off."
XeonXeonIntel's x86 server processors that often have much in common with their high-end desktop processors.  Unlike Itanium, people do sometimes use Xeon processors in home PCs.
XMPExtreme Memory Profile(Extreme Memory Profiles)  Intel's version of EPP, an extension of SPD for overclocking.