Azure blob storage - uploading very slow
===

I have the trial account in the azure blob storage. I try to upload 100000 generated files from my local machine. The operation already have duration over 17 hours and uploaded only ~77000 files.
All files created by a simple bash-script:

    for i in {1..100000}
    do
        echo $i
        echo $i > $1\\$i.txt
    done

Code for the uploading:

    using(var stream = File.OpenWrite(textBoxManyUploadFileName.Text))
    using(var writer = new StreamWriter(stream)) {
    	foreach(var file in Directory.GetFiles(textBoxManyUploadFrom.Text)) {
    		Guid id = Guid.NewGuid();
    		storage.StoreFile(file, id, ((FileType)comboBoxManyUploadTypes.SelectedItem).Number);
    		writer.WriteLine("{0}={1}", id, file);
    	}
    }

    public void StoreFile(Stream stream, Guid id, string container) {
    	try {
    		var blob = GetBlob(id, container);
    		blob.UploadFromStream(stream);
    	} catch(StorageException exception) {
    		throw TranslateException(exception, id, container);
    	}
    }

    CloudBlob GetBlob(Guid id, string containerName) {
    	var container = azureBlobClient.GetContainerReference(containerName);
    	if(container.CreateIfNotExist()) {
    		container.SetPermissions(new BlobContainerPermissions {
    			PublicAccess = BlobContainerPublicAccessType.Container
    		});
    	}
    	return container.GetBlobReference(id.ToString());
    }

The first 10000 files have bean uploaded by 20-30 minutes then the speed decreased.
I think it may due to the fact that the file names are GUID and Azure tries to build the clustered index.
How to speed up? What is the problem?