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    <p>You might try removing the BufferedWriter and just using the FileWriter directly. On a modern system there's a good chance you're just writing to the drive's cache memory anyway.</p> <p>It takes me in the range of 4-5 seconds to write 175MB (4 million strings) -- this is on a dual-core 2.4GHz Dell running Windows XP with an 80GB, 7200-RPM Hitachi disk.</p> <p>Can you isolate how much of the time is record retrieval and how much is file writing?</p> <pre><code>import java.io.BufferedWriter; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.io.Writer; import java.util.ArrayList; import java.util.List; public class FileWritingPerfTest { private static final int ITERATIONS = 5; private static final double MEG = (Math.pow(1024, 2)); private static final int RECORD_COUNT = 4000000; private static final String RECORD = "Help I am trapped in a fortune cookie factory\n"; private static final int RECSIZE = RECORD.getBytes().length; public static void main(String[] args) throws Exception { List&lt;String&gt; records = new ArrayList&lt;String&gt;(RECORD_COUNT); int size = 0; for (int i = 0; i &lt; RECORD_COUNT; i++) { records.add(RECORD); size += RECSIZE; } System.out.println(records.size() + " 'records'"); System.out.println(size / MEG + " MB"); for (int i = 0; i &lt; ITERATIONS; i++) { System.out.println("\nIteration " + i); writeRaw(records); writeBuffered(records, 8192); writeBuffered(records, (int) MEG); writeBuffered(records, 4 * (int) MEG); } } private static void writeRaw(List&lt;String&gt; records) throws IOException { File file = File.createTempFile("foo", ".txt"); try { FileWriter writer = new FileWriter(file); System.out.print("Writing raw... "); write(records, writer); } finally { // comment this out if you want to inspect the files afterward file.delete(); } } private static void writeBuffered(List&lt;String&gt; records, int bufSize) throws IOException { File file = File.createTempFile("foo", ".txt"); try { FileWriter writer = new FileWriter(file); BufferedWriter bufferedWriter = new BufferedWriter(writer, bufSize); System.out.print("Writing buffered (buffer size: " + bufSize + ")... "); write(records, bufferedWriter); } finally { // comment this out if you want to inspect the files afterward file.delete(); } } private static void write(List&lt;String&gt; records, Writer writer) throws IOException { long start = System.currentTimeMillis(); for (String record: records) { writer.write(record); } writer.flush(); writer.close(); long end = System.currentTimeMillis(); System.out.println((end - start) / 1000f + " seconds"); } } </code></pre>
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    1. CO@rozario each write call should only produce about 175MB and then delete itself. if not, you'll end up with 175MB x 4 different write calls x 5 iterations = 3.5GB of data. you might check the return value from file.delete() and if it's false, throw an exception.
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