What is the l2 cache for the model with a release price of $669?
CREATE TABLE "250_nm" (
  "model_number" text,
  "s_spec_number" text,
  "frequency" text,
  "l2_cache" text,
  "fsb" text,
  "mult" text,
  "voltage" text,
  "tdp" text,
  "socket" text,
  "release_date" text,
  "part_number_s" text,
  "release_price_usd" text
);
SELECT "l2_cache" FROM "250_nm" WHERE "release_price_usd"='$669';