Here are some of the most well-known SF door-stoppers:
Tolkien’s The Lord of the Rings is up there at 470,000 words. It was the very first mega-long book I read. I was twelve years old. Although I was a voracious reader, the books I had read up until that time were more the Narnia and Enid Blyton size. Yes, The Lord of the Rings created the fantasy trilogy phenomenon, and you can quibble that it’s really three books, but it was only released in three volumes originally because of the paper shortage after World War II. I read it in the intended form and in which it has generally been published since, which is as a single book. It's often cited as the longest genre novel of all time—but it isn’t.
It is pipped by Stephen King’s The Stand, which I’m reading at the moment, at 472,376 words. Interestingly, the original published version in 1978 wasn’t that long at 322,000 words, but the Kingster decided to publish the version he had originally written before his publishers made him cut it. I’m really enjoying it, but it’s taking me a lot longer to get through because life seems to get in the way now more than it did when I was twelve. I wonder whether he knew that by publishing the extended version, he would be overtaking Tolkien? King has form in the door-stopper genre: It was 445,134 words.
George R R Martin cracked the 400,000-word mark twice in his Song of Ice and Fire series with A Storm of Swords at 422,000 words and A Dance with Dragons at 420,000 words. Apparently, he was worried about the length in the earlier books in the series and took great pains to keep them down to a modest 300,000 words by moving chapters to the next volume. That process will eventually catch up with you, I guess. Since we’re still waiting for the series conclusion, I think it’s too early to discount his efforts in the largest genre book of all time stakes.
Others in the over 400,000 category are Neal Stephenson’s Cryptonomicon (415,000), Diana Gabaldon’s An Echo in the Bone (the seventh Outlander novel) (402,000), and Patrick Rothfuss’ The Wise Man's Fear (400,000).
But if you’re looking for the longest SF novels of all time, it can sometimes come down to genre definitions and whether you only include best-sellers. Here are some of the contenders: Tad Williams’ To Green Angel Tower (520,000), Diana Gabaldon’s The Fiery Cross (502,000) and A Breath of Snow and Ashes (501,000), Mary Gentle’s Ash: A Secret History (500,000), and Brandon Sanderson’s Oathbringer (495,000).
You have to admire writers who can produce high-quality writing over such enormous word lengths. But does size ultimately matter? I'll explore this in part 2.