I've experienced more than one recent instance where the term "Speed Metal" has been discussed. Primarily, if it actually exists, and if it is a valid term to describe a particular sound within the greater metal subgenre.
"Labels" and "subgenres" by their nature are highly subjective, but enough of a general consensus remains within the metal scene that they make for an "intellectual shorthand"; labeling bands into particular subgenres enables fans to quickly describe a basic, general sound that a particular band may fit into. Black Metal is generally accepted to feature heavy doses of sweep picking, blastbeats, high pitched vocals. That's obviously not necessarily true, but if a person says "Emperor plays Black Metal", fast sweeps, high pitched screams, and blastbeats are what comes to mind, right? These labels aren't meant to be perfect or rigid; they just serve to guide conversation by offering some basic point of reference.
Thus we accept labeling bands as Black Metal, or Death Metal, or Thrash Metal, Doom Metal, Power Metal, etc even though the artists don't fit perfectly or oftentimes even agree with the label the metal public place on their music. Sometimes, we even accept vague terms like "Avantgarde Metal" or "Experimental Metal" to describe a band who delves into previously uncovered territory within the greater metal genre (often times these terms disappear once enough bands populate that particular sort of sound that a distinguishing characteristic can be used to describe such bands, thus we encounter terms like Djent or Post-Metal, at which point labelling begins to reach into the absurd...)
This brings us to the term "Speed Metal" and thus, my opinions towards said term. "Speed Metal", in my opinion, is a term INVENTED not by fans of metal, but by relatively ignorant journalists who needed to brand certain sounds during and following the NWOBHM movement. The late 70's saw the emergence of Motorhead and Iron Maiden, both who arrived onto the scene with heavy influences from the 70's punk scene. While Punk Rock could hardly be fit into a single sound itself (see: Blondie vs The Misfits), metal bands seeking to evolve from the Sabbath sound began infusing the faster tempos and dirtier edge of hardcore punk into their sound, laying the groundwork for the emergence of Thrash Metal. Important to note that I am personally no expert on the NWOBHM movement (primarily because I'm just not that interested in listening to very many of the 2nd tier bands, besides Angel Witch), but the NWOBHM movement essentially birthed Thrash and Power Metal.
The terms "Thrash Metal" and "Power Metal" clearly conjure very different ideas. Thrash Metal by its nature was nastier sounding, with more emphasis on distorted crunch and a rhythmic pounding, but not limited in terms of vocal delivery. I'm no fan of most Power Metal artists, but the genre is trademarked by clean sounding bands with an emphasis on soloing and in many cases keyboards along with operatic-styled vocals. The common thread between the two genres however, is that as byproducts of the NWOBHM movement, they both played their style of music at a faster pace than artists before them. That brings us to our problem.
I've heard the term "Speed Metal" used to describe a range of artists who play dramatically different styles of metal. One person posted on a comment thread that "Speed Metal" made him think of bands like Kreator, Sodom, and Helloween.
Well, let's compare, shall we?
Sodom "Nuclear Winter"
Exactly what, besides playing fast, do these 2 bands, from the same country and the same era, have in common? Nothing. And that's ultimately my argument. "Speed Metal" is a USELESS term to describe the sound of a band because it can be used to encompass almost every up-tempo metal artist from the 80's. Fuck, is Bathory "Speed Metal"? What about Venom? Morbid Angel? Suggesting those bands were "Speed Metal" would be met with condescension, and rightfully so. According to Wikipedia, Ian Christe attempts to describe "Speed Metal" as a cleaner sort of Thrash Metal, with emphasis on "classical melodies". Basically, saying it occupies some sort of space between Thrash and Power Metal. In my opinion, it's a needless invention of a space for a term that otherwise has no applicable usage.
Ultimately, the best metal music is made by bands who aren't completely limited to a specific subgenre's aesthetics. It doesn't really matter if a band is tr00 to performing Black, Death, Doom, whatever-Core; if they're competent artists they will shine though. Labels aren't THAT important in the scheme of things. However, "Speed Metal" is a term that tells me NOTHING about what a band sounds like, but it DOES tell me something about the person using the term. Primarily that you need to put down Guitar World or Revolver and spend more time nerding out on Metal Archives and Encyclopedia Metallium like the rest of us=D