diff --git a/convert.py b/convert.py
index 5468af1730ef44..0466853f01ae9a 100755
--- a/convert.py
+++ b/convert.py
@@ -39,6 +39,7 @@
 ARCH=gguf.MODEL_ARCH.LLAMA
 NAMES=gguf.MODEL_TENSOR_NAMES[ARCH]
 
+DEFAULT_CONCURRENCY = 8
 #
 # data types
 #
@@ -717,21 +718,21 @@ def bounded_parallel_map(func: Callable[[In], Out], iterable: Iterable[In], conc
     with factory(max_workers = max_workers) as executor:
         futures: List[concurrent.futures.Future[Out]] = []
         done = False
-        for i in range(concurrency):
+        for _ in range(concurrency):
             try:
-                nexti = next(iterable)
+                futures.append(executor.submit(func, next(iterable)))
             except StopIteration:
+                done = True
                 break
-            futures.append(executor.submit(func, nexti))
-        while not done or futures:
+
+        while futures:
             result = futures.pop(0).result()
-            while len(futures) < concurrency:
+            while not done and len(futures) < concurrency:
                 try:
-                    nexti = next(iterable)
+                    futures.append(executor.submit(func, next(iterable)))
                 except StopIteration:
                     done = True
                     break
-                futures.append(executor.submit(func, nexti))
             yield result
 
 def check_vocab_size(params: Params, vocab: Vocab) -> None:
@@ -850,13 +851,13 @@ def do_item(item: Tuple[str, LazyTensor]) -> (DataType, NDArray):
         return (lazy_tensor.data_type, tensor.ndarray)
 
     @staticmethod
-    def maybe_do_quant(item: Tuple[DataType, NDArray]) -> NDArray:
+    def maybe_do_quantize(item: Tuple[DataType, NDArray]) -> NDArray:
         if item[0] == DT_Q8_0:
             return quantize_array_q8_0(item[1])
         return item[1]
 
     @staticmethod
-    def write_all(fname_out: Path, ftype: GGMLFileType, params: Params, model: LazyModel, vocab: Vocab) -> None:
+    def write_all(fname_out: Path, ftype: GGMLFileType, params: Params, model: LazyModel, vocab: Vocab, concurrency: int = DEFAULT_CONCURRENCY) -> None:
         check_vocab_size(params, vocab)
 
         of = OutputFile(fname_out)
@@ -873,11 +874,11 @@ def write_all(fname_out: Path, ftype: GGMLFileType, params: Params, model: LazyM
         of.write_tensor_info()
 
         # tensor data
-        ndarrays = bounded_parallel_map(OutputFile.do_item, model.items(), concurrency = 8)
+        ndarrays = bounded_parallel_map(OutputFile.do_item, model.items(), concurrency = concurrency)
         if ftype == GGMLFileType.MostlyQ8_0:
-            ndarrays = bounded_parallel_map(OutputFile.maybe_do_quant, ndarrays, concurrency = 8, max_workers = 8, factory = ProcessPoolExecutor)
+            ndarrays = bounded_parallel_map(OutputFile.maybe_do_quantize, ndarrays, concurrency = concurrency, max_workers = concurrency, factory = ProcessPoolExecutor)
         else:
-            ndarrays = map(OutputFile.maybe_do_quant, ndarrays)
+            ndarrays = map(OutputFile.maybe_do_quantize, ndarrays)
 
         start = time.time()
         for i, ((name, lazy_tensor), ndarray) in enumerate(zip(model.items(), ndarrays)):
@@ -1073,12 +1074,13 @@ def main(args_in: Optional[List[str]] = None) -> None:
     parser.add_argument("--dump",        action="store_true",    help="don't convert, just show what's in the model")
     parser.add_argument("--dump-single", action="store_true",    help="don't convert, just show what's in a single model file")
     parser.add_argument("--vocab-only",  action="store_true",    help="extract only the vocab")
-    parser.add_argument("--outtype",     choices=["f32", "f16", "q8_0"], help="output format (default: based on input)")
+    parser.add_argument("--outtype",     choices=["f32", "f16", "q8_0"], help="output format - note: q8_0 may be very slow (default: f16 or f32 based on input)")
     parser.add_argument("--vocab-dir",   type=Path,              help="directory containing tokenizer.model, if separate from model file")
     parser.add_argument("--outfile",     type=Path,              help="path to write to; default: based on input")
     parser.add_argument("model",         type=Path,              help="directory containing model file, or model file itself (*.pth, *.pt, *.bin)")
     parser.add_argument("--vocabtype",   choices=["spm", "bpe"], help="vocab format (default: spm)", default="spm")
     parser.add_argument("--ctx",         type=int,               help="model training context (default: based on input)")
+    parser.add_argument("--concurrency", type=int,               help=f"concurrency used for conversion (default: {DEFAULT_CONCURRENCY})", default = DEFAULT_CONCURRENCY)
     args = parser.parse_args(args_in)
 
     if args.dump_single:
@@ -1132,7 +1134,7 @@ def main(args_in: Optional[List[str]] = None) -> None:
         params.ftype = ftype
         print(f"Writing {outfile}, format {ftype}")
 
-        OutputFile.write_all(outfile, ftype, params, model, vocab)
+        OutputFile.write_all(outfile, ftype, params, model, vocab, concurrency = args.concurrency)
         print(f"Wrote {outfile}")