How to Choose the Best PECPool Stratum Server

Learn how to select the best PECPool Bitcoin stratum server, test regional servers and ports, configure reliable backup pools, reduce rejected shares, and improve mining stability.

Selecting the correct stratum server is an important part of configuring a Bitcoin ASIC miner. The best server is not always the one that appears geographically closest. Internet routing, packet loss, local filtering, ISP quality, network congestion, and port accessibility can all affect the connection between your miner and the mining pool.

A properly selected PECPool stratum server can provide:

• More stable pool connectivity
• Fewer mining interruptions
• Faster share submission
• Lower stale or rejected share rates
• More consistent worker status
• Reliable automatic failover

This guide explains how to select, test, and prioritize PECPool Bitcoin stratum servers for Antminer, WhatsMiner, and other compatible SHA-256 ASIC miners.

What Is a Stratum Server?

A stratum server is the connection point between your ASIC miner and the mining pool. Through this connection, PECPool sends mining jobs to your miner and receives the shares calculated by the device.

1. PECPool sends mining jobs to the miner.
2. The miner performs SHA-256 calculations.
3. The miner submits completed shares to PECPool.
4. PECPool validates the submitted shares.
5. Valid shares are assigned to the correct mining account and worker.

A complete stratum address contains three main parts:

• The connection protocol
• The server hostname
• The port number

Example:

stratum+tcp://btc-eu.pecpool.com:3333

In this example:

• stratum+tcp:// is the connection protocol.
• btc-eu.pecpool.com is the server hostname.
• 3333 is the port number.

Do not enter a normal website address such as cp.pecpool.com in the miner's Pool URL field. ASIC miners require a stratum address rather than a normal web page address.

Official PECPool Bitcoin Stratum Servers

PECPool provides several regional Bitcoin stratum servers. Miners can select the most suitable connection according to their location and actual network conditions.

Region	Server	Available Ports
Global	btc.pecpool.com	3333, 443, 25
United States	btc-us.pecpool.com	3333, 443, 25
Europe	btc-eu.pecpool.com	3333, 443, 25
Russia	btc-ru.pecpool.com	3333, 443, 25
Asia	btc-as.pecpool.com	8443, 443, 25
Iran	btc-ir.pecpool.com	8443, 443, 25
Iran Alternative	btc.pecpool.cc	8443, 443, 25

Always enter the official hostname exactly as shown. Do not replace the hostname with a fixed IP address unless PECPool Support specifically instructs you to do so.

Server IP addresses may change because of infrastructure maintenance, load balancing, routing improvements, or service migrations. Using the official hostname allows the miner to resolve the correct destination automatically.

Understanding Regions and Ports

The server region identifies the general infrastructure location or routing destination. The port identifies the network entry point used by the miner to connect to that server.

For example, the following addresses use the same Europe server but different ports:

stratum+tcp://btc-eu.pecpool.com:3333
stratum+tcp://btc-eu.pecpool.com:443
stratum+tcp://btc-eu.pecpool.com:25

If one port is blocked by a router, firewall, ISP, or local network policy, another supported port on the same regional server may still work.

Port 3333

Port 3333 is a commonly used Bitcoin stratum port. It is available on the PECPool Global, United States, Europe, and Russia servers.

Example:

stratum+tcp://btc-eu.pecpool.com:3333

This port is normally a suitable first choice when the network allows standard mining traffic.

Port 8443

Port 8443 is available on the PECPool Asia, Iran, and Iran Alternative connections.

stratum+tcp://btc-as.pecpool.com:8443
stratum+tcp://btc-ir.pecpool.com:8443
stratum+tcp://btc.pecpool.cc:8443

Port 443

Port 443 is provided as an alternative stratum port. It can be useful when another port cannot be reached from the miner's network.

stratum+tcp://btc-as.pecpool.com:443

Using port 443 does not automatically mean that the mining connection uses HTTPS or encryption. The connection protocol shown in the Pool URL remains stratum+tcp://.

Port 25

Port 25 is another alternative PECPool stratum port.

stratum+tcp://btc-eu.pecpool.com:25

Although port 25 is commonly associated with email services, PECPool also provides it as an alternative mining connection port on its official stratum servers.

Some internet providers or firewalls may restrict this port. It should therefore be tested rather than assumed to work.

Which Server Should You Choose?

Start with the server closest to the physical location of your mining operation, but do not make the final decision based only on geographical distance.

A nearby server may still perform poorly when:

• The ISP uses an inefficient network route.
• International routing is congested.
• Packet loss is present.
• The selected port is filtered.
• DNS resolution is unstable.
• The connection frequently resets.
• The route becomes unstable during peak hours.

A more distant server with a stable route can perform better than a nearby server with frequent packet loss or disconnections.

The recommended selection process is:

1. Start with the nearest regional server.
2. Test whether the hostname resolves correctly.
3. Test the supported ports.
4. Configure the server in the miner.
5. Confirm that accepted shares are increasing.
6. Monitor the connection for several hours.
7. Compare the result with alternative regional servers.

Suggested Starting Configuration by Region

The following configurations are recommended starting points. Actual performance depends on the miner's ISP, routing, firewall, and local network conditions.

United States

Pool 1: stratum+tcp://btc-us.pecpool.com:3333
Pool 2: stratum+tcp://btc.pecpool.com:443
Pool 3: stratum+tcp://btc-eu.pecpool.com:25

Europe

Pool 1: stratum+tcp://btc-eu.pecpool.com:3333
Pool 2: stratum+tcp://btc.pecpool.com:443
Pool 3: stratum+tcp://btc-us.pecpool.com:25

Russia and Nearby Regions

Pool 1: stratum+tcp://btc-ru.pecpool.com:3333
Pool 2: stratum+tcp://btc-eu.pecpool.com:443
Pool 3: stratum+tcp://btc.pecpool.com:25

Asia

Pool 1: stratum+tcp://btc-as.pecpool.com:8443
Pool 2: stratum+tcp://btc.pecpool.com:443
Pool 3: stratum+tcp://btc-eu.pecpool.com:25

Iran

For mining networks affected by regional or international connectivity interruptions, the following diversified configuration can be used:

Pool 1: stratum+tcp://btc.pecpool.cc:8443
Pool 2: stratum+tcp://btc-as.pecpool.com:443
Pool 3: stratum+tcp://btc-eu.pecpool.com:3333

This configuration uses different hostnames, regions, and ports to provide greater connection diversity.

Other Locations

Begin with the Global server and add the nearest regional connections as backups:

Pool 1: stratum+tcp://btc.pecpool.com:3333
Pool 2: Nearest regional PECPool server on port 443
Pool 3: Another regional PECPool server on a supported port

After testing, move the most stable server to Pool 1.

Why Three Stratum Addresses Are Recommended

Most ASIC miners provide three pool configuration fields:

1. Pool 1 is the primary connection.
2. Pool 2 is the first backup connection.
3. Pool 3 is the second backup connection.

If Pool 1 becomes temporarily unreachable, the miner can automatically try Pool 2 and then Pool 3. This can reduce downtime during:

• Regional routing problems
• Internet provider interruptions
• Temporary server maintenance
• Port filtering
• DNS problems
• International network disruptions
• Firewall rule changes

A strong configuration should preferably use different hostnames, regions, and ports.

For example, the following configuration uses only one regional hostname:

Pool 1: stratum+tcp://btc-eu.pecpool.com:3333
Pool 2: stratum+tcp://btc-eu.pecpool.com:443
Pool 3: stratum+tcp://btc-eu.pecpool.com:25

This can protect against a blocked port, but it does not provide the same routing diversity as using multiple regional hostnames.

A more diversified configuration is:

Pool 1: stratum+tcp://btc-eu.pecpool.com:3333
Pool 2: stratum+tcp://btc.pecpool.com:443
Pool 3: stratum+tcp://btc-us.pecpool.com:25

How to Test a PECPool Stratum Server

The most useful test is an actual mining connection. However, preliminary network tests can help determine whether the hostname and port are reachable.

Tests should be performed from a computer connected to the same router, gateway, or internet connection used by the mining devices.

Test 1: Check DNS Resolution

DNS converts a hostname such as btc-eu.pecpool.com into an IP address.

Windows PowerShell:

Resolve-DnsName btc-eu.pecpool.com

Windows Command Prompt:

nslookup btc-eu.pecpool.com

Linux:

getent hosts btc-eu.pecpool.com

Another Linux option is:

nslookup btc-eu.pecpool.com

A successful result should normally return at least one IP address.

If DNS resolution fails:

• Check the internet connection.
• Review the router's DNS configuration.
• Test another DNS resolver.
• Check for local filtering.
• Restart the router or DNS service.
• Test the hostname from another internet connection.

Do not permanently replace the official hostname with the returned IP address.

Test 2: Check the TCP Port

A hostname may resolve correctly while the selected stratum port is blocked.

Windows PowerShell:

Test-NetConnection btc-eu.pecpool.com -Port 3333

Testing port 443:

Test-NetConnection btc-eu.pecpool.com -Port 443

Look for the following result:

TcpTestSucceeded : True

Linux using Netcat:

nc -vz btc-eu.pecpool.com 3333

Testing port 443:

nc -vz btc-eu.pecpool.com 443

A successful TCP test confirms that the tested hostname and port can be reached from that network.

However, it does not confirm that:

• The mining account name is correct.
• The worker format is correct.
• The miner will remain connected for several hours.
• Shares will be accepted normally.

These items must be verified from the ASIC miner and the PECPool panel.

Test 3: Check Ping

Windows:

ping btc-eu.pecpool.com

Linux:

ping -c 10 btc-eu.pecpool.com

Ping can provide basic information about:

• Approximate round-trip time
• Obvious packet loss
• Basic network reachability

Ping should not be used as the only test. A server or firewall may ignore Ping requests while the stratum port remains fully operational.

• A successful Ping does not guarantee stable mining.
• A failed Ping does not necessarily mean the stratum server is unavailable.
• The TCP port test and accepted shares are more important.

How to Compare Server Latency

Lower latency is generally helpful because submitted shares can reach the pool sooner. However, latency alone does not determine the best server.

Example Server A:

Average latency: 45 ms
Packet loss: 4%
Frequent disconnections: Yes

Example Server B:

Average latency: 85 ms
Packet loss: 0%
Frequent disconnections: No

Server B may provide better mining performance because its route is more stable, even though its latency is higher.

Use the following priority order when comparing servers:

1. Successful and stable connection
2. No persistent packet loss
3. Accepted shares increasing normally
4. Low stale or rejected share rate
5. No frequent pool switching
6. Consistent last-share time
7. Latency

Do not select a server only because it produced the lowest single Ping result.

Configure the Miner for a Real Test

Enter the selected PECPool servers in the miner's pool configuration.

Pool 1

URL: stratum+tcp://btc-eu.pecpool.com:3333
Worker: myaccount.miner01
Password: x

Pool 2

URL: stratum+tcp://btc.pecpool.com:443
Worker: myaccount.miner01
Password: x

Pool 3

URL: stratum+tcp://btc-us.pecpool.com:25
Worker: myaccount.miner01
Password: x

Use the same mining account and worker name in all three pool entries.

The recommended worker format is:

AccountName.WorkerName

Example:

myaccount.miner01

The Pool Password field is not your PECPool login password. When no special pool password is required, use:

x

Never enter any of the following in the pool password field:

• Your PECPool login password
• Your email password
• Your Two-Factor Authentication code
• Your API Secret
• Your Bitcoin private key
• Your wallet seed phrase

How to Confirm That the Server Is Working

After saving the pool configuration, open the miner's status page and check:

• Active pool URL
• Pool status
• Accepted shares
• Rejected shares
• Stale shares
• Last share time
• Real-time hashrate
• Average hashrate
• Pool switching history
• Connection errors
• Miner logs

A successful connection should normally show:

• The pool as Alive, Active, Connected, or Working
• Accepted shares increasing
• Recent share submissions
• Stable hashrate
• No repeated authorization errors
• No continuous connect and disconnect cycle

The exact status names depend on the miner manufacturer and firmware.

Verify the Connection in PECPool

After the miner begins submitting valid shares:

1. Sign in to the PECPool control panel.
2. Open Monitor.
3. Select the correct mining account.
4. Locate the worker.
5. Check its Online status.
6. Review the current and average hashrate.
7. Review the last-share time.
8. Check rejected or stale shares.
9. Review the hashrate chart.

A newly connected or restarted worker may require approximately 10 to 20 minutes to appear or change to Online status.

Do not consider a server reliable only because the worker remains Online for a few minutes. Observe the connection long enough to detect:

• Periodic disconnections
• Peak-hour routing problems
• Repeated failover events
• Large gaps in the hashrate chart
• Delayed shares
• Increasing rejected shares
• Different daytime and nighttime performance

How Long Should You Test a Server?

Initial Test

Observe the server for at least 30 to 60 minutes and confirm that:

• The connection remains active.
• Accepted shares continue increasing.
• The worker remains Online.
• No repeated authorization or socket errors occur.

Extended Test

Observe the connection for several hours or a complete operating day to evaluate:

• Connection stability
• Peak-hour performance
• Share consistency
• Rejected or stale shares
• Failover events
• Hashrate chart gaps

Avoid changing servers repeatedly after only a few minutes. Frequent changes make accurate performance comparison difficult.

What Makes a Good Primary Server?

A suitable Pool 1 address should:

• Connect successfully after the miner starts.
• Remain connected for long periods.
• Receive accepted shares consistently.
• Produce few rejected or stale shares.
• Avoid long gaps in last-share time.
• Avoid repeated Pool Dead errors.
• Remain stable during peak internet hours.

The primary server does not need to have the absolute lowest Ping result. Long-term stability is more important than a small latency difference.

What Makes a Good Backup Server?

Pool 2 and Pool 3 should remain usable when the primary server or network route has a problem.

Good backup addresses should preferably use:

• A different PECPool hostname
• A different server region
• A different supported port
• A route that is less likely to fail with Pool 1

Example:

Pool 1: Europe on port 3333
Pool 2: Global on port 443
Pool 3: United States on port 25

Periodically test the backup addresses. A configuration that worked several months ago may no longer be the best option for the current ISP or network route.

Common Problems and Solutions

The Nearest Server Does Not Connect

Try the following:

1. Use another supported port on the same hostname.
2. Test the Global server.
3. Test another nearby region.
4. Try another DNS resolver.
5. Perform a TCP port test.
6. Check the router and firewall.
7. Test the connection through another ISP.

Ping Works but Mining Does Not Connect

Possible causes include:

• The stratum port is blocked.
• The Pool URL is incomplete.
• The worker format is incorrect.
• The miner's gateway is incorrect.
• A firewall allows Ping but blocks TCP.
• The mining account is incorrect.

Run a TCP port test and review the miner's connection log.

Ping Fails but Mining Works

This can occur when Ping responses are disabled while the TCP stratum port remains available.

If:

• The pool is shown as Alive or Connected,
• Accepted shares are increasing, and
• The worker is Online,

the failed Ping result alone is not a reason to change the server.

Port 3333 Does Not Work

Try another supported port for the selected region:

443

or:

25

If none of the ports work, test another official PECPool regional hostname.

Port 443 Works but Port 3333 Does Not

This normally indicates that the network path, router, ISP, or firewall treats the ports differently.

You can continue using the working official port when:

• Accepted shares increase normally.
• The connection remains stable.
• Rejected shares are not consistently high.
• The miner does not repeatedly disconnect.

Do not assume the connection is encrypted only because port 443 is being used.

The Miner Frequently Switches to Pool 2

This may indicate that Pool 1 is unstable or temporarily unreachable.

Check:

• Pool 1 hostname
• Pool 1 port
• Miner logs
• Router logs
• DNS resolution
• Packet loss
• Internet interruptions
• Firewall rules

If Pool 2 consistently performs better, move that address to Pool 1 after completing sufficient testing.

All Three Pools Show Dead

Check:

• Internet access
• Router gateway
• DNS configuration
• Ethernet cable
• Network switch
• Firewall rules
• ISP restrictions
• Stratum address spelling
• Port numbers
• Miner firmware

Also confirm that the address begins with:

stratum+tcp://

The Worker Is Online but Hashrate Is Low

A low pool hashrate does not always indicate a stratum server problem.

Check:

• How long the miner has been online
• Hashboard status
• Miner temperature
• Power supply status
• Hardware errors
• Miner restarts
• Rejected shares
• Overclocking settings
• Firmware stability

Pool hashrate is calculated from valid shares received over time and may temporarily differ from the miner's local real-time value.

Rejected or Stale Shares Increase After Changing Servers

Possible causes include:

• Higher network latency
• Packet loss
• Unstable routing
• A distant server region
• Frequent reconnects
• Miner instability

Return to the previous stable server or test another official PECPool region. Compare performance over a reasonable period rather than using only a small number of shares.

Important Configuration Mistakes to Avoid

• Do not use a normal website URL as the Pool URL.
• Do not enter cp.pecpool.com as a stratum server.
• Do not enter your wallet address as the worker name.
• Do not enter your PECPool password as the pool password.
• Do not use unofficial PECPool server addresses.
• Do not replace official hostnames with fixed IP addresses.
• Do not configure only one pool address.
• Do not use the same worker name for unrelated miners.
• Do not select a server based only on one Ping result.
• Do not assume port 443 automatically provides encryption.
• Do not change servers repeatedly without observing the result.

Recommended Server Selection Process

1. Identify the nearest PECPool regional server.
2. Test DNS resolution for the hostname.
3. Test the available ports.
4. Select two additional PECPool servers as backups.
5. Enter the three addresses in Pool 1, Pool 2, and Pool 3.
6. Use the same account and unique worker name in all entries.
7. Save the configuration.
8. Check the miner's pool status.
9. Confirm that accepted shares are increasing.
10. Verify the worker in PECPool.
11. Observe the connection for several hours.
12. Move the most stable server to Pool 1.
13. Periodically verify that Pool 2 and Pool 3 remain reachable.

Final Checklist

• All server hostnames are official.
• The complete stratum+tcp:// format is used.
• The primary server is stable from the mining location.
• The selected port is reachable.
• Pool 2 uses a reliable alternative address.
• Pool 3 provides another independent backup.
• Different regions or routes are used where practical.
• The worker format is correct.
• The pool password is not the PECPool account password.
• The active pool shows a connected status.
• Accepted shares are increasing.
• The worker is Online in PECPool.
• Rejected or stale shares are not consistently high.
• The miner is not switching pools repeatedly.
• The backup pools have been tested.

Choose Stability, Not Only the Lowest Ping

The best PECPool stratum server is the server that provides the most reliable mining connection from the actual location of your mining devices.

Evaluate each server using:

• TCP connectivity
• Accepted shares
• Rejected and stale shares
• Worker status
• Last-share time
• Connection history
• Long-term stability

Configure three official PECPool addresses, use different regions and ports where practical, and periodically review their performance.

A stable server with slightly higher latency is normally a better choice than a low-latency server that frequently disconnects or loses shares.