Questions on enhancing wdex4 performance (currently getting 10MB/s on gigabit ethernet)

Below is the case request I sent to WD support, I am posting it on the community in case someone here can help.

I am running wdex4 NAS with latest firmware (1.05.30) and with 4 WD Red 6TB drives within configured using RAID10 for a total redundant storage of about 12TB. Unfortunately due to infrastructure reqs. I am unable to connect WDEX4 directly to the router. Please do not suggest connecting to the router directly since that just isn’t possible. (Most routers have only 4 ports anyway so it is an unreasonable requirement).

Instead the setup is as follows:

  • Gigabit router port --> Gigabit switch1 -----> WDEX4 (connected using ethernet ports 1 & 2)

  • Gigabit switch1 --> Windows 7 Desktop (using gigabit network adapter)

(all connections made using Cat6 cable)

  • While Gigabit Ethernet has a maximum of 125MB/s yet under the non-optimal setup described above, I am only getting a disappointing sustained rate of 10MB/s. It starts of at 15-20 then quickly in 30 seconds or so goes down to 10. This is when transferring files from my desktop to WDEX4. This is quite useless, I need to have at least 50MB/s for this NAS to be usable.


  1. I have looked up the word usb in your full user manual to determine if it is possible to connect wdex4 to my desktop directly via usb and how to go about this (i.e. connect 1 port or both) so that the file transfers are done via dual usb 3.0. Unfortunately the manual only references using usb to connect other hard drives, nothing about using USB for file transfer from a desktop directly. Is it supported to connect WDEX4 to my desktop directly via usb3.0? If so how do I do it? Can I or must I use both USB ports? Keeping in mind USB 3.0 speed is 60MB/s which would be perfect if wdex4 can actually achieve it. My desktop has the needed USB3.0 ports.

  2. Since I have WDEX4 hooked up to the gigabit switch using both the primary and secondary gigabit ethernet ports, I have enabled the (Link Aggregation) option however surprisingly, your documentation does not even offer a description about what what each link aggregation option means and the best circumstances to use each one. I currently have it set to Active Backup. Keeping in mind the setup described above, which option would your engineers recommend for best performance?

3.For initial loading of data onto the WDEX4 which software do you recommend for optimal speed? Besides windows explorer. I am using fastcopy 2.11 and like windows explorer it yields a sustained rate of 10MB/sec with added reliability since it will log any failed transfers.

  1. Eventhough I have all the media streaming options turned off (under media tab and on my shares), and the latest firmware where this is supposed to be fixed. WDEX4 is still indexing my files and creating hidden folders. This is wasting time, resources, and valuable disk space, and making my job of comparing the file size on the source and target to ensure proper file transfer very difficult since there are always extra files and folders! I don’t want any files automatically added to my shares on WDEX4. I don’t want .wdmc or .nflc_data or .twonky. Since I don’t use the features media streaming, dlna etc. I just want EDEX4 to function as a 24/7 max reliability hard drive. Please let me know what I need to do to accomplish this. I already have an ssh connection to the drive and can connect to it with putty and winscp and execute any commands you provide. However please make them such that I would not have to run the commands on every reboot. Finally please specify if I can enable the cloud option so that I can browse and access my files without those hidden folders being created or if enabling the cloud access would automatically force creating the files keeping in mind I’m not interested in wd photos app, only in the cloud app so that I can download files on my wdex4 remotely. I am however willing to give up that option if using it requires the stupid hidden folders to be created.

  2. If I add a second gigabit NIC on my desktop, would it work if I connect WDEX4 directly to this second nic? such that my desktop would be connected to the router through a switch and wdex4 would only be connected to my desktop’s nic or if it will help I can connect one gigabit port to the switch that connects to the router and the other directly to my desktop. In that case what would be the ideal link aggregation setting?

  3. It would be great if you can update future firmware so that the requirement to connect the WDEX4 directly to the router is not required and no longer impacts speed. Such that the wdex4 and a desktop can network directly.


Welcome to the Community.

While you are waiting for WD Support I can at least confirm the USB port is an input port only and does not allow for the unit to work as a regular USB drive; it’s used for expansion. On the other hand, disabling the listed services will require assistance from advanced Users within the WD Community as this is not supported by WD.

1 Like

Thanks for the response Trancer.


  1. I just got a response from support today but it was only that they are still working on my question.

  2. I managed to increase the speed to 25 MB/S. This is a very nice improvement but still would like to get this to 50 if possible.

The extra speed was possible after I set link aggregation to round robin and I also turned of the (Jumbo frame) option eventhough jumbo frame was supported by my switch and my desktop NIC. Also this only applies to transfering files from my desktop to WDex4. The reverse, downloading from wdex4 is maximum 15MB/S. I also noticed that even when I’m downloading a single file, the CPU on wdex4 goes to 100% occasionally but never stays there at least. Also to allow for a control group of sorts I transfered files within my desktop from one WD internal HD to another and the speed was 70MB/sec sustained so clearly the desktop upload bandwidth is not an issue. Moreover I checked the network utilization bandwidth on my desktop nic while transferring to and from WDex4. It only reaches 25-30% at most.

Thanks to the Mod kindly escalating the ticket. I got the response below from wd support. I am adding it in case it will be helpful and possibly if someone may have something to add. The bulk of the questions has been answered though. Strangely there seems to be a disconnect between what actual network experts think of the product vs what support believes is the target audience. When I spoke to the administrator where I work (small bus. 150+ users), his opinion was that while WD is the undisputed king of hard drives and we should buy drives from no one else, when it comes to NAS, his recommendation was to always stick to Synology for professional networks. My decision to still buy wd anyway was that I didn’t think anyone else would have tested the 6TB red drives. In fact you need the latest firmware before EX4 will work with them. This performance bottleneck has however been an unpleasant surprise. In any case the bulk of the questions are answered so I will mark this as an accepted response.

1.      WD-Support : Direct connections between a desktop system and the EX4 are not possible. The USB connectors are to provide additional storage and direct upload and download options.
The backup tab in the unit’s dashboard allows you to either upload content from or backup the unit’s shares to a USB direct attached storage device.

Hani : I had considered this a backup option in case I couldn’t get the gigabit lan to function well. Fair enough. It was an incorrect assumption on my part since I should have read the documentation prior to purchase. In any case if the hardware supports this still, it would be an excellent feature to add for a subsequent firmware to make the product more suitable for home use and none Networking experts. Meanwhile perhaps making it clear the USB ports cannot be used in this manner in the product description would be benificial to all.

2.      WD-Support : Link aggregation and associated transfer performance and reliability increase when this feature is enabled will rely on your network infrastructure to see any benefit. All devices including the target PC will need to support port bonding both physically and logically port to be effective. Each sub option offers different pros and cons in terms of speed and connectivity. Simply connecting two Ethernet cables will not see any gain except for fault tolerance. The EX4 is a expert

series product and will require the correct knowledge of networking technologies to fully make use of this feature.

Hani :Unfortunately this did not answer the question, or at least even provide a brief explanation of the usage of each option. I understand it’s an expert series product, and while I’m not a networking expert. I do hold a degree in computer science, so some basic documentation to point one in the right direction from the people who made the product would not have been too much to ask. Besides the wd description says this is meant for both home and small office. the network setup was provided and a recomendation from the wd experts on the wd product was requested but denied. In any case I did some searching and found a reviewer of EX4 who was strangely more generous with providing information about this eventhough they’re not being paid to provide the information. Here it is for reference:

    Round-robin (balance-rr)
    Transmit network packets in sequential order from the first available network interface (NIC) slave through the last. This mode provides load balancing and fault tolerance.
    Storage manufacturers like NetApp (uses a proprietary BSD OS) have deprecated the use of Round Robin on their products as it tends to cause issues related to packet loss. In such cases use of LACP (link aggregation control protocol) is favored.
    Active-backup (active-backup)
    Only one NIC slave in the bond is active. A different slave becomes active if, and only if, the active slave fails. The single logical bonded interface’s MAC address is externally visible on only one NIC (port) to avoid distortion in the network switch. This mode provides fault tolerance.

    XOR (balance-xor)
    Transmit network packets based on [(source MAC address XOR’d with destination MAC address) modulo NIC slave count]. This selects the same NIC slave for each destination MAC address. This mode provides load balancing and fault tolerance.

    Broadcast (broadcast)
    Transmit network packets on all slave network interfaces. This mode provides fault tolerance.
    Creates aggregation groups that share the same speed and duplex settings. Utilizes all slave network interfaces in the active aggregator group according to the 802.3ad specification.
    Adaptive transmit load balancing (balance-tlb)
    Linux bonding driver mode that does not require any special network switch support. The outgoing network packet traffic is distributed according to the current load (computed relative to the speed) on each network interface slave. Incoming traffic is received by one currently designated slave network interface. If this receiving slave fails, another slave takes over the MAC address of the failed receiving slave.
    Adaptive load balancing (balance-alb)
    Includes balance-tlb plus receive load balancing (rlb) for IPV4 traffic, and does not require any special network switch support. The receive load balancing is achieved by ARP negotiation. The bonding driver intercepts the ARP Replies sent by the local system on their way out and overwrites the source hardware address with the unique hardware address of one of the NIC slaves in the single logical bonded interface such that different network-peers use different MAC addresses for their network packet traffic.

3.      WD-Support : For network transfers, the FTP protocol appears to yield the best rate in terms of performance when transferring files. However a USB drive can be connected to the EX4 with the content on and then an upload from the USB device to the EX4 can be initiated from the backup tab.

Hani :Excellent, thank you for providing these options. At 70MB the transfer twice from my computer to a USB thumb drive and fom the drive to EX4 should yield 35MB/s not counting time to plugin the drive which I suppose should still be faster than using gigabit lan at 24MB/s allbeit limiting the file size I can transfer at that speed. I shall compare ftp using winscp to do ftp transfer vs fastcopy and see which will serve better.

4.      WD-Support : I would like to inform you that we are aware of the .WDMC files being visible in some circumstances and we are currently investigating this. By disabling remote access in the UI you will be able remove these folders from view and with the media server disabled there should be no increase in the folder size.

Hani :Confirmed, I turned off the (media serving) option on each of my shares, then turned off the media streaming option fromt he media screen. I did not have to disable remote access though. In any case that item seems to be ok now.

5.      WD-Support : If the underlying network configuration is in place then connecting two LAN cables to your switch and having the EX4 connected by both connections, you would then probably be able to benefit from the Link aggregation feature of the EX4. However this would again rely on the functionality of your switch and configuration of the correct OS options if supported.

Hani : As mentioned I already have 2 LAN cables on the switch with link aggregation. Although you did not recommend which link aggregation option to use in your answer to question 2.

6.      WD-Support : The ex4 and your PC can be directly networked together or via the switch. Static IP addressing would be necessary to avoid passing traffic via the router or your router would need to be removed from the equation and again would require knowledge of network protocols and configuration. When directly connected together without any intervening devices via the supplied Ethernet cable. The EX4 and the target PC can gain self assigned IP addresses and communicate with each other so long as they are within the same sub net.

Hani :ok, thank you for confirming this is an option and providing a hint on the network setup needed. I shall pursue this. While obviously this means EX4 would lose internet access, I am more interested in using it as a big fast external hard disk than as a cloud connected one since it is clear it cannot accomplish both without a direct router connection.